The U.S. criminal-justice system is a mass of conflicts and contradictions. While trying to protect innocent people from criminals, law enforcement agencies also must try to protect the innocent from being mistaken for criminals. Science should be purely impartial in this process—it should prove as much as possible that pieces of physical evidence are what they are supposed to be and that they came from where witnesses and investigators say they came from (Carvey, 2004). In order to meet changes and social needs, law enforcement should employ a large number of forensic scientists from different fields of research and investigation.
Today, in the U.S. legal system’s adversarial approach, there really is no such thing as the impartiality of evidence. As science becomes more complex, the need for experts to translate the meaning of science becomes more acute, but not even these experts are impartial: Both the prosecution and the defense in criminal trials, and both parties in civil trials, routinely have their own scientific experts testify on nearly every aspect of the evidence.
This leads to the question of whether it is possible to find an expert who will defend any position—as an attorney does—or whether there is so much scientific uncertainty in physical evidence that it really is not possible to use any such evidence in a conclusive manner (Carvey, 2004).
It is clear that some people are in prison today because of bad science done in the name of criminal justice: bad laboratory procedures; exculpatory evidence withheld from a defendant because of continual public and political pressure to gain convictions; and scientific evidence that is far from certain, but which has been argued persuasively by prosecution experts. Each of these people known to be free when the killing occurred, and living within some arbitrary geographic area—the city, the county, or whatever—could be contacted, interviewed, and investigated. A large number of forensic professionals will help to improve the quality of services provided (Fisher, 2000).
Some critics claim that modern technology and computerization will help to reduce the number of forensic professionals and scientists. On the other hand, both the technology itself cannot solve all problems and the increasing complexity of research investigations. As computers become more complex, they also become more prone to error. Further, the more people who have access to these computers, the greater the chances that human error, political bias, or just plain curiosity will endanger our liberties. When the often disparate facts of one’s life are collected and collated, the data become information that can be used to identify, track, and even judge a person (Fisher, 2000).
Today, as the twenty-first-century approaches, even three-and four-officer rural departments have computers in police cars. Computerized crime-analysis reports are not difficult programming feats; essentially, data are logged by patrol area or beat, time of day, day of the week, type of crime, and any details about the M.O. (modus operandi, or method of operation). The computer then can simply break down daily, weekly, monthly, or annual crime statistics by these various factors. The need to increase the number of forensic scientists is caused by the complexity of technology and testing procedures (Horswell and Edwards 1997).
Crime might be lessened, criminal convictions might be made easier, and positive identification would be enhanced, but on the other hand, such a “universal identifier” would create a civil-liberties jungle. Despite notification on numerous documents that the Social Security number is not to be used for identification purposes, it is used in such a way extensively—for instance, on driver’s licenses, school records, and medical records (Horswell, 2000).
This identifier can be used to compare and match computerized records by governmental agencies in order to create lists of people who fit a number of criteria—the creation of computer profiles. Any third-level bureaucrat, with access to a personal computer and networking equipment, can call up information about a person from dozens of federal agencies just by flagging a Social Security number—such confidential information as tax returns, loan applications, and participation in government grants and social-welfare programs. Beyond government, these records are used by insurance companies, credit-checking agencies, and even advertising and marketing companies. An increasing number of professionals will help to improve service quality and daily operations of law enforcement (Siegal et al 2000).
The mass of criminal-justice data that must be entered, even in a modest-size police department, often puts a strain on resources. Frequently, the fact that someone has been arrested is entered into the computer within minutes, but the facts that charges were dropped or that the person was found not guilty take days or months to be entered, or are never entered at all. A number of people have sued the police for arresting them using out-of-date, incomplete, or false data, and police officers have even sued NCIC administrators for putting them at risk in civil suits.
Courts often have ruled in favor of people arrested falsely, and many data-integrity cases are settled out of court; either result often takes months or years and has a high financial and emotional cost. In this case, an increased number of forensic scientists will help to improve data analysis and reduce the number of claims (Siegal et al 2000).
In sum, an increased number of forensic scientists will help law enforcement to improve its productivity and performance. Solving routine crimes is one of the most difficult tasks for law enforcement. Forensic scientists may help in training young detectives; they also may, by organizing information and forcing a person who enters data to follow a logical sequence of questions, get better data from uniformed officers who make reports, and give detectives better information to work with.
References
Carvey, H. (2004). Windows Forensics and Incident Recovery (The Addison-Wesley Microsoft Technology Series). Addison-Wesley Professional.
Fisher, B. A. J. (2000) Techniques of Crime Scene Investigation, 6th edn, CRC Press.
Horswell, J. and Edwards, M. (1997) Development of quality systems accreditation for crime scene investigators in Australia, Science and Justice, 37 (1), pp. 3-8.
Horswell, J. (2000) Suspicious deaths, in Siegal et al. (eds), Encyclopaedia of Forensic Sciences, Academic Press, London, pp. 462-6.
Siegal et al. (eds), (2000). Encyclopaedia of Forensic Sciences, Academic Press, London.
In the past decade, forensic science has become a powerful field due to its significance as supporting evidence in criminal cases. The development of handling and analysis techniques of DNA samples has led forensic investigators to rely on the information forensic science can offer. The combination of DNA analysis with the study of surrounding insects (entomology) and pollen (palynology) has resulted in an efficient and effective method in investigating criminal cases (Leclair et al., 2004). The inclusion of forensic data in criminal investigations has thus transformed the process of conviction and to a certain extent, has overturned particular verdicts upon review of old cases. Unfortunately, in many cases the convicted individual is usually sentenced to death and the DNA evidence is too late to overturn the sentence.
The significant upgrades in the field of information technology have also enhanced the capabilities of criminal investigation to solve old cases. These cases that have occurred in the past, ranging from a few years to decades, are technically referred to as cold cases. The computerization of criminal records has generated a powerful database tool, making the activity of checking old files easier and more efficient. Currently, every local police department employs a database that is networked to both state and national databases for a quick reference. CODIS is a two-part DNA database that is currently maintained in police departments—one serves as a catalog of criminal cases, while the other database contains files of missing persons. The path of criminal case investigation to date is initiated by generating a DNA profile based on what is collected at the crime scene. This particular DNA profile, linked to the rest of the databases in the network, will search for similarities in DNA profiles previously submitted to the database. Should there be a match, the criminal linked to that particular DNA profile will be pulled out and the investigation proceeds to the next step. Such automated method of searching for matches with existing records in the databases saves a significant amount of time. However, it should be understood that the chances of finding a match in the database depends on the number of DNA samples that were collected in different crime scenes through the years. It is also important that a DNA profile has been generated from every DNA sample that was collected from the crime scene.
In the case of missing persons, a DNA profile database will be helpful in identifying bodies that have been recovered and are difficult to recognize in terms of facial features. Such obstacles of unidentifiable human remains are often observed among cold cases due to the degree of composition of the human body over time. In an extreme case, the remains of a person may consist of only bones and a few tissue parts, hence the employment of DNA isolation and profiling will definitely be helpful in identifying the body. The same conditions could be applicable to incidents such as fires, explosions and plane crashes, wherein there is much deterioration of human flesh and it is difficult to identify a body based mainly on physical features.
It should be noted that the development of DNA profile databases not only makes the retrieval of criminal information simpler and faster, such computerized file systems may also lower the crime rate. The positive identification of DNA samples have led to higher conviction rates thus reducing the possibility of future criminal acts of these individuals. DNA profiles are very unique in that it does not generate false positive matches. The system of DNA sequencing identifies the number of nucleotide bases that are unique to each individual and can only occur at a specific sequence and a number of repeats,, distinguishing bodies belonging to relatives and which body belongs to the mother, the father, and the child.
The power of DNA profiling can be employed on cold cases because it allows the isolation of DNA from old evidences that may contain biological samples that are associated with the crime, including old blood stains, saliva, hair and skin. The DNA molecule is extremely stable because it can withstand years unchanged as long as it is not exposed to fire and/or acid. In the case of fire crime scenes, DNA can still be isolated from the inner area of the teeth, or the enamel, which is protected from heat by the surrounding tooth structure.
Forensic crime scene investigation currently employs the study of human remains and this also involves extraction of DNA from the tissues for inclusion in the polymerase chain reaction, which is an enzymatic amplification of specific DNA sequences of a particular DNA sample, be it the victim, the suspect or any other individual in the crime scene, through a series of varying temperatures in order to generate sample-specific DNA patterns that are visualized on an electrophoretic gel. The specific DNA sequences employed in forensic DNA analysis are known as short tandem repeats (STRs), which are present across the entire genome of each individual. The power of STR analysis is based on the premise that each individual carries a unique STR pattern that can distinguish one person from another, just the same as how fingerprinting works. Forensic DNA analysis is more reliable than fingerprinting because DNA can never be erased or changed, unlike fingerprints which could be removed when the fingers of a suspect are burned or are covered by gloves, resulting in fingerprint-free hands. The principle of STR analysis comes from the concept that these DNA sequences have a unique number of copies in each individual and the probability of having two individuals having the same number of copies exponentially decreases as more DNA locations or loci are analyzed.
Results from the STR analysis of forensic DNA samples may show either the same or different DNA profile between the suspect’s actual DNA and the DNA collected from the crime scene. These sentences in blue do not make sense. If the results show a different DNA profile from that of the DNA collected from the crime scene, then the suspect can be indicted from the criminal investigation. However, if the DNA profile from the STR analysis is similar, then the suspect can convicted immediately. The forensic scientist must then compute for the probability that an individual picked out through a random process would general an identical profile as that employed in the STR analysis. The principle of population genetics is the core behind this computation, which involves a combination of statistics, mathematics, genetics and biology. The Hardy-Weinberg Law of Equilibrium is applied to cases that show positive results in the STR analysis. This determines the chances that an individual selected at random would have a similar DNA profile with those STR sequences which were analyzed (Cash et al., 2003). Each STR sequence is treated as a genotype or a genetic combination, which is specific to each DNA region in the human genome. Hence, when determining the probability of having an individual with the same DNA profile for 10 genotypes, the product of all the genotype frequencies should be calculated.
Though forensic DNA analysis is very powerful and reliable, this method is also subject to human error which could then result in incorrect convictions. The employment of forensic DNA analysis is very critical in cases wherein no other supporting evidence can be collected from the crime scene, the victim, or the suspect. Errors in handling forensic DNA may include contamination, wherein the samples employed in the analysis contains a mixture of more than one biological organism, which may be either another individual different from the actual analyzed person, as well as DNA from bacteria that may be present at the site of collection. Another error in handling forensic DNA samples may also involve degradation of the sample, which pertains to the breakage of the DNA in the samples collected (Coble and Butler, 2005). Intact DNA is necessary when performing STR analysis and degradation of DNA could result from exposure of the collected samples to heat or reagents such as acid, bleach, alcohol or preservatives such as formalin or acetone. Heat associated in a crime scene may be due to a fire or burning of only a particular part of the crime scene where the collected sample was situated. Intact DNA is essential for the success of an STR analysis because the STR sequences have to be located in the entire genome of an individual. Any breakages in the genome would result in an erroneous result in the analysis wherein either an STR region may not be identified because that particular region could not detected because it was probably located in an area that was degraded. It should be understood that although forensic DNA analysis requires specific conditions for sample collection and DNA handling, the procedure is very reliable and robust that even samples that have been stored in a preservative or alcohol for decades or centuries may be employed as source of DNA for STR analysis.
In order to prevent contamination of samples that will be used for forensic analysis, quality-control procedures have been designed in order to have a standardized method of conducting the collection and handling of material. The use of protective wear such as gloves, face masks and laboratory gowns are necessary in handing forensic samples. In addition, structural equipment such as HEPA-filtered air duct systems, biological hoods, and sanitized rooms are also necessary to ensure that contamination does not occur during the analysis. The systematic labeling and recording of forensic samples and DNA material are also important in the success of DNA analysis. It is easier for the forensic scientist to rule out any problems with contamination and just focus on analyzing any similarities in the DNA profiles of the individuals being investigated in the forensic laboratory.
Aside from employing forensic DNA analysis in crime investigations, STR analysis may also be employed in the identification of victims in mass fatalities or disasters such as bombings, tsunamis, plane crashes and mass graveyards (Budimlija et al., 2003). In such conditions, wherein not only two individuals (victim and suspect) are involved, a more tedious process of collection, handling and analysis of DNA samples is conducted. Forensic DNA analysis of victims in a mass disaster needs reference samples which actually pertain to material facilitating the positive identification of a body. Two kinds of reference samples are generally employed in this type of forensic analysis. The DNA samples collected from the victim’s family members are employed as a reference sample. Personal effects of a victim are also employed as reference samples such as biological specimens that may have been collected before death or antemortem, biopsies from the hospital in which the victim may have gone to for medical consultation, or bloodstain cards of the victim that may be been issued during a biomedical test. Simple antemortem reference samples are also admissible for forensic analysis and these may include toothbrushes, razors, and shavers. However, these reference samples may generate errors in the analysis because these items may also be contaminated with DNA from other individuals or other biological organisms. If contamination is present in these reference samples, the positive identification of a victim’s body may fail or may result in mixed DNA profiles, which in turn will lead to a confusing identification. Another way to further strengthen the positive result generated from an antemortem reference sample is to analyze a family member or a second antemortem reference sample. It is thus important that kinship analysis be performed to further strengthen the results obtained when using antemortem reference samples. These reference samples are generally more reliable than personal items such as toothbrushes and razors.
When conducting DNA profile assays, it is important that a significant number of STR patterns are analyzed (Alonso et al., 2005). It has been determined that analyzing 13 to 17 STR patterns generate more reliable results in DNA analysis so that the DNA profiles collected will show more discriminatory power in terms positively identifying a victim, especially when there is a need to distinguish the victim from the assailant. In terms of family references, it is possible to employ different combinations of DNA from the victim’s family. For example, one or both parents of a victim may be employed to provide their DNA as reference sample in the identification of their son/daughter, who is the victim of a disaster. Another combination of a reference sample may involve the biological matter of the victim, together with their child or children. It is essential that the children be involved in this type of reference sample because it will show the mixture of STR patterns that are present in the child and the source can be determined, whether each STR pattern comes from either the father or the mother. A reference sample that only involves the biological mate will not be helpful to a forensic DNA analysis because there is no biological connection between the victim and the partner and thus the child or children should be included in a forensic analysis if the biological mate will participate in the forensic analysis. Siblings of the victim may also serve as reference samples for DNA analysis, as long as the sibling has at least one common parent with the victim. This common parent provides that biological or DNA connection between the sibling and the victim’s DNA, be it a paternal or a maternal biological connection in terms of STR patterns. Reference samples are often collected in the form of buccal swabs or blood and are processed for both nuclear and mitochondrial DNA.
In addition to DNA analysis, entomology may also be employed in crime scene investigation. The presence of insects in specific larval stages may generate information on the time of death of a victim. The information generated from such analysis may be combined with the data generated from DNA analysis to provide a bigger and more informative description of a crime or a disaster. The use of entomological data in forensic analysis may also provide information of the sequence of death of individuals in a crime scene. For example, if a mother and child were found dead in their home, the presence of insect larva at particular stages of development will provide information on whether the mother or the child died first. The sequence of death may be determined on the victim’s body by checking which larva is at a later stage of development, meaning that this victim died first and the other victim showing larva at a younger stage of development means that he died later. The weather, in relation to the presence of the larva, will also provide clues to the time of death of a victim. It is scientifically known that during winter, the insects take a longer time to migrate and produce larva, hence if a body is found during the winter, death must have ensued earlier because the larva presence in a body must that it must have taken some time for the insects to find this body and nest on it.
This type of crime scene investigation is usually associated with difficulties in isolating intact DNA due to the exposure of tissues to high temperatures of the fire. However, there have been frequent testing and optimization of DNA isolation protocols that it is now possible to increase the amount of DNA yield even if the tissue source has been burned in a fire or has been kept in preservatives such as formaldehyde for months, years, or decades (as in the case of mummified corpses). A better approach to DNA isolation involves the retention of the 0.5 mM EDTA solution with the pulverized bone in order to prolong chelation of calcium ions and other EDTA-inhibitors as well as the employment of collagenase for enzymatic dissociation of tissues (Schmerer et al. 1999). After such incubation, proteinase K will be introduced, as detailed in the original procedure.
The analytical power of crime scene investigation in combination with forensic analysis provides another powerful and reliable tool in the investigation of crimes and disasters (Alonso et al., 2005). However, it is important that precautionary measures be taken in order to prevent any false positive identification which is turn influence convictions of suspects as well as wrongful sentencing to either life imprisonment or death.
The act of crime scene investigation is designed to observe individuals, areas or objects that are of particular interest to an investigator in order to collect information and evidence that may be associated with a suspect and his related criminal activities (Walker, 2001). Physical surveillance is a method of examination of a particular area that is linked to a crime scene or a suspect. This may include inspecting the area where the crime took place, as well as the victim’s and suspect’s homes, vehicles, and paraphernalia. Examination will cover both the conditions of the places and items, as well as the position of the places and items in the particular areas.
Physical surveillance is important in a crime scene investigation because it provides a way for the investigator to reconstruct the scene and make inferences on what actually happened during the incident (Gardner, 2005). Any area that is associated with a crime is identified as soon as a crime has been established or reported. In addition, these particular areas are protected from any type of disruption by putting a crime scene tape along the perimeter of the area concerned. It has been reported that the most complicated part of an investigation is the establishment and protection of the boundaries of a crime scene because the signs related to a scene are often elusive to an investigator. Other investigators employ search dogs to facilitate the establishment and tracking of a crime scene.
Photography is commonly employed in the physical surveillance of a crime scene. This visual documentation of an area is very helpful to an investigator because it physically records the features of the area before any other activity is performed to the crime scene. Physical surveillance also involves marking all potential evidences to the crime. In addition to photographs, sketches of the crime scene are also important in physical surveillance of a specific area. Sketches are generally considered as essential information of crime scenes because these serve as detailed notes of the investigation, although the diagrammatic representation is of less quality than a simple photograph. Sketches provide measurements of the crime scene, including distances between two points of interest that are located within the area under investigation. An investigator often starts with a rough sketch and eventually moves on to a final sketch that is drawn to scale. These sketches are commonly employed as models during court hearings and trials because these provide the floor-plan of an area of interest, the elevation of the area and its details and other critical dimensions that may be helpful in the analysis of a crime scene.
Physical surveillance serves more purposes in a crime scene investigation than a technical surveillance because it provides the investigator with sufficient evidence that may be important in linking a specific suspect to a particular crime. Technical surveillance does not provide the specific details that physical surveillance provides because it does not provide any associative details that are critical to an investigation (Gottfredson and Hirschi, 1990). In addition, physical surveillance provides a view of the crime scene through an observer’s eyes and this usually provides a neutral view of the area, removing any biases and discrimination of certain items and areas. Physical surveillance also provides a better understanding of a crime incident through the note-taking that is performed on the area, including any traces of struggle or bullet holes. It also assists the investigator in reconstructing the sequence of events that are related to the crime, including the initial moments of what was said, done or executed by the victim and the suspect.
A forensic crime scene investigator is responsible for employing techniques in physical anthropology, human osteology and molecular analysis in criminal cases. A forensic crime scene investigator is trained in the identification of human bodies in different states or conditions such as decomposed, mutilated or burned. There are even cases wherein the human body is beyond recognition and it takes a forensic crime scene investigator to identify the person’s body in order to assist in further investigation a criminal case. The development of techniques in handling and analysis of human skeletal structures has influenced police investigators to rely on any information forensic anthropologists can offer (Prado et al., 1997). In combination with DNA analysis and the study of surrounding insects (entomology) and pollen (palynology), an efficient and effective method in investigating criminal cases can be conducted (Leclair et al., 2004). The inclusion of forensic data in criminal investigations has thus transformed the process of conviction and to a certain extent, has overturned particular verdicts upon review of old cases.
References
Alonso A, Martín P, Albarrán C, García P, de Simón L, Iturralde MJ, Fernández-Rodríguez A, Atienza I, Capilla J, García-Hirschfeld J, Martínez P, Vallejo G, García O, García E, Real P, Álvarez D, León A and Sancho M (2005): Challenges of DNA profiling in mass disaster investigations. Croat. Med. J. 46(4):540-548.
Budimlija ZM, Prinz MK, Zelson-Mundorff A, Wiersema J, Bartelink E and MacKinnon G (2003): World Trade Center human identification project: Experiences with individual body identification cases. Croat. Med. J. 44:259-63.
Cash HD, Hoyle JW and Sutton AJ (2003): Development under extreme conditions: Forensic bioinformatics in the wake of the World Trade Center disaster. Pac. Symp. Biocomput. 2:638-53.
Coble MD and Butler JM (2005): Characterization of new mini-STR loci to aid analysis of degraded DNA. J. Forensic Sci. 50:43-53.
Gardner R (2005): Practical Crime Scene Processing and Investigation. Boca Raton: CRC Press.
Gottfredson MR and Hirschi T (1990): A General Theory of Crime. In: Jacoby JE (ed.): Classics of criminology, 3rd ed. Illinois: Waveland Press, Inc.
Leclair B, Fregeau CJ, Bowen KL and Fourney RM (2004): Enhanced kinship analysis and STR-based DNA typing for human identification in mass fatality incidents: the Swissair flight 111 disaster. J. Forensic Sci. 49:939-53.
Prado VF, Castro AK, Oliveira CL, Souza KT and Pena SD (1997): Extraction of DNA from human skeletal remains: Practical applications in forensics sciences. Genet. Anal. 14:41-44.
Schmerer WM, Hummel S and Herrmann B (1999): Optimized DNA extraction to improve reproducibility of short tandem repeat genotyping with highly degraded DNA as target. Electrophoresis 20:1712-1716.
Yoshida Y Fujita Y and Kubo S (2004): Forensic casework of personal identification using a mixture of body fluids from more than one person by Y-STR analysis. J. Med. Investig. 51:238-242.
Walker PL (2001): A bioarchaeological perspective on the history of violence. Annu Rev Anthropol 30: 573–596.
Forensic toxicology is the study and analysis of samples with the aim of finding out whether they contain any chemicals, drugs, or toxic substances. A forensic toxicologist collects biological samples from subjects and performs scientific tests using complex instruments. This discipline is interesting because of its wide range of applications, availability of interaction opportunities among professionals from different areas of specialization, and great access to numerous career opportunities. New chemicals and drugs are developed daily due to advancements in technology. Therefore, it is necessary for scientists to create new methods of analysis to identify and classify those drugs and chemicals in samples. The availability of numerous opportunities makes forensic toxicology an exciting discipline. Possible areas of work include the military, government agencies, law enforcement agencies, hospitals, private establishments, and the academic sector.
Forensic toxicology requires advanced and specialized training that takes several years. An individual interested in the discipline should have a Bachelor’s degree in forensic science or related disciplines such as natural sciences, chemistry, and biology (Toxicology n.d). Forensic toxicologists take courses in areas that include pharmacology, analytic chemistry, cellular physiology, chemistry, toxicology, and pathophysiology (Toxicology n.d). In certain cases, doctorate-level education is required. Other skills that are necessary for success include research skills, interpretation and analysis of data, and laboratory training.
Forensic toxicologists take biological samples from subjects and test them for various substances such as poison, chemicals, and drugs. Other substances that are identified in samples include alcohol, poisonous gases such as carbon monoxide, and metals (Molina, 2009). Types of samples collected for analysis include blood, urine, hair, bile, gastric juice, and certain body organs and tissues (Molina, 2009). Professionals in this field are involved in cases that include sexual exploitation, homicide, violence, driving under the influence, and child custody. The type of sample used is determined by the complexity of the case under investigation.
Different types of instruments are used in forensic toxicology to perform various functions. These instruments include microscopes, syringes, needles, endoscopes, enema sets, blood gas analyzers, polymerase chain reaction (PCR) apparatus, electrocardiography machines (ECG), ultracentrifuges, gas chromatographs, different types of mass spectrometers, capillary electrophoresis instruments, enzyme-linked immunosorbant assay (ELISA) apparatus, and different types of chromatography (Molina, 2009). These instruments are used in the detection, identification, and classification of different compounds and chemicals in samples.
Types of certification available include Certification as a Forensic Toxicology Specialist and Certification as a Diplomate of the Board (Certification as a Forensic Toxicology Specialist n.d). These certifications are only issued by the American Board of Forensic Toxicology (ABFT). Applicants must possess the necessary education requirements and at least three years of professional experience in forensic toxicology (Certification as a Forensic Toxicology Specialist n.d). Certification is completed only after applicants pass a test issued by the ABFT on different principles of forensic toxicology. Certificates are valid for five years and cannot be transferred from one individual to another.
In conclusion, forensic toxicology is an exciting discipline that involves the analysis of samples with the aim of finding out whether they contain drugs, toxic gases, or toxic chemicals. Education requirements include a background in toxicology or any life science. Specimens studied include blood, urine, bile, gastric juice, and body tissues. Types of evidence sought include poisonous metals, toxic gases, alcohol, and drugs. Forensic toxicologists use different types of instruments that include microscopes, endoscopes, analysis machines, polymerase chain reaction (PCR) apparatus, electrocardiography machines (ECG), and ultracentrifuges among others. Certification is only offered by the American Board of Forensic Toxicology (ABFT).
References
Certification as a Forensic Toxicology Specialist (n.d). Web.
Molina, D. K. (2009). Handbook of Forensic Toxicology for Medical Examiners. New York: CRC Press.
Investigation of a homicide will usually begin at the place where the body is found also known as the primary crime scene. It is important that any item found on the primary crime scene should be handled with utmost care because it may constitute evidence (Saferstein, 2011).
This makes it important to have the crime scene secured before arrival of the forensic investigative team. In most homicide cases, the primary crime scene will yield an abundance of evidence, usually physical evidence that can be submitted to the laboratory for forensic analysis in order to associate the crime scene, victim, and suspect with each other (Turvey, 2011).
It is important to understand that in a homicide case there might be two or more crime scenes besides the location where the body of the deceased has been found. These new or other crime scenes may include the places where the actual assault that led to death occurred, an automobile was used to move the body to a new location, and where any physical or related evidence will be found (this may include place where parts of the body are found) (Miletich, 2003).
The physical evidence that can be found in the primary and other related crime scene will include objects, body materials, and impressions. The objects that may be found at the crime that that can be sent for forensic analysis include weapons, tools, firearms, notes, bullets, cars, cigarette and cigarette butts.
The body material will include blood, semen, hair, tissue, spittle, urine, feces, and vomit. The impressions that can be found will include fingerprints, tire tracks, footprints, palm prints, tool marks, bullet holes, dents ad breaks. The physical evidence found at the scene will be analyzed by forensic investigators to see if they were involved in the crime scene or their contribution to the demise of the victim (Braswell & Fish, 2010).
Class vs. Individual Characteristics
In forensic investigation, evidence found at a crime scene or is being investigated can be placed under class characteristics, individual characteristics or both characteristics. Class characteristics are the properties of evidence that will be associated with groups and not individual objects or substances.
The measurable features of the item will indicate relationship with a restricted group source because of design factors that have been identified before manufacture. Examples of evidence that may show class characteristics include the width of a screwdriver, the width of groove impression, and others. Individual characteristics are the properties of evidence that can be ascribed to a common source.
This is usually with a very high degree of certainty. The measurable features of the evidence that will show its uniqueness may include marks found on objects that will be produced as a result of imperfections and or irregularities on surfaces. Examples of evidence that will show individual characteristics will include fingerprints, bullet striations, impressions marks made by cutting objects and others (Geberth, 2009).
In summary, we can say that class characteristics are “Intentional or design characteristics that would be common to a particular group or family of items,” (FireArms, 2011). Individual characteristics are “marks produced by the random imperfections or irregularities of tool surfaces. These random imperfections or irregularities are produced incidental to manufacture and/or caused by use, corrosion, or damage. They are unique to that tool and distinguish it from all other tools” (FireArms, 2011).
The class characteristics that an examiner will look for in a bullets/casings will be riffling pattern from the barrel that fired the bullet while the individual characteristics that will be investigated will be the individual characteristics of the firearm that were passed to the bullet during firing. In fingerprints, the class characteristic that is sought is fingerprint pattern while the individual characteristics hat an investigator will look for is the ridge pattern because no two people have the same ridge pattern.
In footwear impression the class characteristics that an investigator will look for is the design of the sole that can narrow it to a particular type of shoe. While looking for the individual characteristic the investigator will look for specific cuts, abraded edges that will make the impression unique. The examiner will look at the size, orientation, location of these imperfections to get the individual characteristics (Geberth, 2009).
References
Braswell, M. C. & Fish, J. T. (2010). Crime Scene Investigation. Amsterdam: Elsevier.
Interviewing is a way of collecting information from a person or a group of people. The type of interview will depend on some factors like; the kind of information, the person to be interviewed and the urgency of the information required. In cases of law, and in the criminal justice system, interviewing the defendant or the person believed to have committed the offence is of great importance. It will not only give information about if he committed the offence but also about a plea of insanity to explain and excuse a crime. (Toufexis 2002).
Main body
In the case at hand, it is important to look at and protect the integrity of the mental evidence. The mental evidence is as important as the physical evidence and it can also be contaminated and corrupted. Forensic psychiatry can be applied in this case. It is the application of the principles of psychiatry to matters of law. The psychiatrist or psychologist is supposed to evaluate whether the accused is mentally competent to stand trial. He should also assess the state of mind of that person during the time he committed that offense. In any interview, there will be things like introduction, rapport building, guidelines for the interview, and a narrative description of the event. There will also be follow up questions and clarification. The step wise interview is appropriate in this case.. (Routine Psychiatric Assessment 2002).
Apart from the above steps which are general for an interview, the steps in this method will usually begin with the most open, least leading, least suggestive form of questioning and then proceed to more suggestive form of questioning when necessary. Such an interview will determine whether the person was insane, whether he has a mental disease, whether he emotionally appreciates the wrongfulness of the actions and if he can be assisted to recover from such an act. (Toufexis 2002).
It can always help to reveal the correct mental status. This is done by giving out open headed questions and not leading questions. One will be able to gather the true and right information if only you aim at seeking the truth and justice. There are different ways of assessing this mental evidence, you can interview the person which is the very common way of gathering information, and you can also interview the witnesses if any. In this case, we interview the person.. (Routine Psychiatric Assessment 2002).
During the interview, there are some important concepts of the clients mental status which should be determined, this include; insanity, emotional expression, thinking and perception. The client might have been insane by the time he committed the crime. A mental psychiatrist should seek to determine if the person has a history of insanity. Such information will determine if the person is able to stand trial or not. (Toufexis 2002).
A person who has stress can react in a way when he does not know if what he does is right or wrong. Judgment will be conducted with the knowledge that this person was stressed and it will therefore be fair. Depression or manic expressions can influence the acts of a person. In general, any form of mental illness or disorder has to be considered during forensic interview. In our case there are possibilities that the person is hallucinating, there is also a possibility that he is suffering stress from the death of the father. (Routine Psychiatric Assessment 2002).
Conclusion
Mental status assessment procedures are vulnerable to error because of interviewer cultural effects. It has to be understood that an individual’s culture can affect his mental state. Spiritual beliefs are some of the issues to be considered in this case where the man argues that he was sent by the gods. The man also believes that he must stay away from parents when searching for employment; he believes on self dependency even though he is not working, these things affect his daily life. These factors must be considered before coming to a strong conclusion about the client’s mental state. (Sommers 1998).
References
Toufexis, A. ( 2002). A psychiatrist’s eye view of murder and insanity. 2009. Web.
Assessment Routine Psychiatric. (2002). Web.
Sommers.J. (1998), Clinical Interviewing, John Wiley and Sons. New York.
Forensic odontology has been used in court for several decades. Since its introduction, the procedure has stood up to scrutiny and is now a valuable part of forensics. It is sometimes credited as being superior to some of the more popular and recognized forms of forensic evidence, such as fingerprints and palm prints. Nevertheless, several important details inherent to the practice, as well as the unimpressive success rate accumulated over the years discourage the use of bite marks as sufficient evidence to sustain a conviction.
Forensic odontology, or forensic dentistry, is responsible for analyzing the bite marks or other impressions left by the suspect’s teeth on the victim’s body or any other object. The impressions are handled and utilized largely in the same way as the fingerprints and other visual representations of the anatomic data: by applying the obtained image to the suspect’s jaw to check for a match. While it has produced a fair amount of helpful evidence that was used to successfully find and convict real dangerous criminals, the procedure was initially seriously unreliable.
The impressions were in most cases redrawn by hand, and since the tissue (the most likely place for the marks) does not have “memory,” they had to be interpreted to obtain details. This basically meant that at least some degree of error was present in the evidence-gathering process. Naturally, the match with the suspect’s teeth was also determined visually. Nowadays, most of the procedures are computerized, which allows for a much better precision.
However, while the image and the model of the jaw are stored in digital format, the actual data in question is still analog, which means it is open to interpretation. This detail differentiates teeth marks from DNA: while the latter is also often represented in visual analog format, the actual data is a highly precise code that can be printed out with the required resolution. The former, on the other hand, is derived from an imprecise analog source and needs to be further verified by relying on human judgment.
Another limitation of the soft tissue as a source of evidence is its ability to restore itself. In the case of John Kunco, who was convicted of rape based on the bite marks on the victim’s shoulder, the imprints were five months old by the time they were obtained by the expertise and had to be retrieved using the ultraviolet equipment (Balko, 2015). The court has been upholding the conviction since then, regardless of the obviously unreliable evidence.
Another notable weakness of the technique is that the evidence is easily modifiable and thus falsifiable. The imprint can be changed by grinding down teeth or simply removing them. In some cases, such removal can be justified (an accident or an unfortunate fall may end in the loss of teeth), which makes an already weak evidence even less reliable.
Certainly, in some exceptional cases, the use of bite marks can serve as a turning point, for instance when additional confirmation is needed or when the suspect has a unique dental imprint. Besides, the presence of bite marks implies the aggression, unlike palm prints, which do not suggest malevolence – only the fact of contact. Positive identification of a bite mark confirms the ill intentions of the perpetrator, which is a huge advantage. Nevertheless, it absolutely requires positive identification, which is not a fail-safe technique in the case of forensic dentistry. Thus, the bite marks alone are certainly not enough to conclusively sustain a conviction and thus should be approached with caution.
Reference
Balko, R. (2015). The path forward on bite mark matching — and the rearview mirror.
Fraud is one major security element that is lagging behind the growth of any organization in the modern world. Fraud robes an organization its rightful acquired resources hence the need to come up with control measures to curb this vice.
Many organizations in the modern world have established security mechanisms to deal with any form of fraud both internal and external fraud. Internal control mechanisms are proving to be more effective when dealing with this vice. In most of the fraud cases in an organization, the master planners are the employees or people who understand the operation procedures of the organization well (Biegelman & Bartow, 2012).
Internal controls have been integrated into business policies and procedures of most organizations. They are effective not only in controlling fraud, but also in protecting the resources of an organization against unnecessary waste (Bayens & Roberson, 2010). They ensure accuracy, reliability, secure compliance with the set organizational policies and at the same time evaluating the performance level of all the business units within an organization.
Generally, internal controls act as the monitoring body of all organization’s operations. It should be the responsibility of all organizational members to play some role in the implementation of internal controls for them to become more effective. This starts right from the management tickling down to junior members of staff whereby, all the members involved should be familiar with the control procedures pertaining to their job responsibilities.
The performance of internal controls mechanism set by a given organization is determined by the control environment, activities, risk assessment, information and communication. According to Goldmann (2010), these elements are normally referred to as elements of internal control. The control environment forms the backbone of internal controls performance consisting of integrity and ethical values, assignment of authority, formulation of policies and procedures in an organization.
Risk assessment is another major element that forms effective internal control mechanisms. This is well illustrated by the assessment of risks from both external and internal sources. It involves the identification and analysis of actual possible risks to achievement of the objectives. Risk assessment should be an ongoing process as the economics and the regulatory conditions keep on changing.
According to Comer, (2003), fraud can happen to anyone and a good case is that of New Scotland Yard where over £ 5 million was stolen by the deputy director of finance and concealed by writing fake payment vouchers.
This is a clear indication that most form of fraud is done by the associates of an organization including employees, customers, agents, suppliers and ex-employees who are motivated by greed. The auditing unit of an organization must identify pertinent information and communicate it in a form that will enable people to perform their responsibilities.
It has been identified that dishonest activities in an organization are done by organization associates and even if done by external individuals, there must be collaboration with the associates of an organization.
It is for this reason that its not wise for an organization to incur extra cost in contracting external services that provide security against fraud and maintaining an in-house department that is well equipped and positioned to handle such fraud. Internal controls measures have the capability of protecting, detecting and punishing the culprits involved without raising the alarm thus protecting the image of an organization to the general public.
This is done by formulating clear authorization procedures, segregation of duties, physical restrictions and monitoring operations (Silverstone & Davia, 2005).
In conclusion, it is evident that in-house controls can be more effective in the detection of possible fraud in an organization as opposed to outsourcing the same services. Internal security controls are also more economical and have the interests of an organization at heart if well equipped and managed.
References
Bayens, G., J. and Roberson, C. (2010). Criminal Justice Research Methods: Theory and Practice. New York: CRC Press.
Biegelman, M., T and Bartow, J., T. (2012). Executive Roadmap to Fraud Prevention and Internal Control: Creating a Culture of Compliance. New York: John Wiley & Sons.
Comer, M., J. (2003). Investigating corporate fraud. London: Gower Publishing.
Goldmann, P. (2010). Financial Services Anti-Fraud Risk and Control Workbook. New York: John Wiley and Sons.
Silverstone, H and Davia, H., R. (2005). Fraud 101: Techniques and Strategies for Detection. New York: John Wiley & Sons.
When a crime has been committed, samples are obtained from the crime scene and sent to the forensic laboratory. In a typical case, a known sample is obtained from a person, mostly in form of a buccal swab, and the results of the DNA analysis compared to the Questioned sample from the crime scene (Thompson 540). Later, a report is made based on the relationship between the donor of known sample and Questioned sample. The paper seek to examine different DNA assessment tools and their uses.
During the DNA investigation in the laboratory, an analysis is performed in nuclear DNA. This 3.3 billion base pairs long chromosomal DNS resides in the nucleus and is available in two copies per cell (Butler 32). It recombines during meiosis before it is passed down from parents to their children. In the early stages of human identification, Bernatzky discovered long repeating sequence in the nuclear DNA and investigated these by performing Restriction Fragment Length Polymorphism studies (4). This technique employs enzymes that cut the DNA at designated sites, which shows a particular pattern of size separation by gel electrophoresis (Bernatzky 5).
Currently, the forensic DNA investigation depends on the assessment of short tandem repeats (STRs) from nuclear DNA (Wambaugh 55). These short DNA sequence repeats occur in abundance throughout the non-coding regions of the nuclear genome. In the laboratory, the STRs are amplified with primers that are appended with fluorescent dyes, and the resulting amplicons are separated by size with capillary electrophoresis to determine the variation in repeats between individuals (Butler 32). Since nuclear DNA recombines in a loci-independent manner, it is very suitable for human identification because this lays a basis for combining the results for all STR loci. By doing so, it is possible to establish identity from a DNA sample.
In some case, STRs may be unfit for investigation because of the low quantity of present DNA to obtain an STR profile (Butler 32). This is mostly the case with hairs and aged teeth and bone samples. In such situations, mitochondrial DNA is the best alternative strategy for DNA investigation (Budowle, Joseph, and Mark 6). Unlike nuclear DNA, mitochondrial DNA is maternally inherited, which limits its resolution to a maternal lineage. However, this characteristics makes is specifically useful in kinship testing and the identification of human remains. The mitochondrial genome resides in the mitochondria of a cell. It is circular, approximately 16.5 kb long and is present in thousands of copies depending on the cell type, compared to the two copies of nuclear DNA in a single cell. The mitochondrial genome is categorized into a coding and non-coding region. The coding region codes for certain genes (Budowle, Joseph, and Mark 8). The non-coding control region of the mitochondrial genome mutates at a higher rate than the coding region. This allows forensic DNA experts to focus their analysis on two or three hypervariable regions found in the non-coding region which contain the most intraindividual variation. since it is smaller in size, the total amount of mitochondrial DNA in a cell is lower than that of the nuclear DNA, but its higher copy number, its shape and the extra level of protection from the environment provided by the double membrane of the mitochondrion increases the level of sensitivity and lays a foundation for greater possibility of recovering substantial mitochondrial DNA for typing of degraded samples (Butler 32).
The evidentiary values of mitochondrial DNA differs from that of nuclear DNA because of its material inheritance; it cannot be used to establish identity. Since there is no recombination of the mitochondrial DNA, all maternal relatives have the same profile, apart from germ-line mutations that may have developed.
Budowle, Bruce, Joseph A. DiZinno, and Mark R. Wilson. “Interpretation Guidelines of mtDNA Control Region Sequence Electropherograms in Forensic Genetics.” Tenth International Symposium. (1999) Web.
Butler, John M. Forensic DNA Typing: Biology and Technology behind STR Markers. San Diego, CA: Academic Press, 2001. Print.
Foran, David R. “Relative Degradation of Nuclear and Mitochondrial DNA: An Experimental Approach.” Journal of Forensic Sciences 5.4 (2006): 766-70. Print.
Thompson, William C. “DNA Testing.” Encyclopedia of Crime and Punishment. By David Levinson. Vol. 2. Thousand Oaks, Calif: Sage Publications, 2002. 537-44. Print.
Wambaugh, Joseph. The Blooding. New York: Morrow, 1989. Print.
A Firearm is a weapon that expels a projectile at high velocity due to rapid combustion of propellants. Often, firearms are associated with crime scenes despite their usefulness in defense. In this regard, forensic experts are mandated with the task of analyzing projectiles generated from gunshots, and their impact on hitting the target (Carper, 2000). This knowledge is paramount in forensic science as it helps investigators of crime to establish the type of weapon and ammunition used in a crime scene. Moreover, the location, angle and distance are determined by analyzing firearms’ evidence. In Canada, with the assistance of forensic experts, several firearms collected from crime scenes have been successfully linked to the suspects (Anderson, 2009).
Firearms studies in forensic sciences are normally subdivided into six groups (Carper, 2000).These include internal firearms analysis, external firearms analysis, target firearms analysis, powder analysis and bullet residues analysis. In internal firearms analysis, bullets energy varies depending on the firearm. For example, a bullet fired from a handgun will have less energy compared to a bullet fired from a rifle. In this regard, more gunpowder is used in the manufacture of rifle cartridges compared to handgun cartridges. This is because different bullet chambers are designed to withstand varying pressures. Consequently, bigger guns accommodate higher pressures compared to smaller guns that are designed to accommodate less coil pressure. With the firing of a bullet, the pressure reduces and expansion of the gas in the barrel occurs. It reaches a point where pressure lessens and acceleration increases with increase in the length of the barrel.
External firearms analysis involves the study of the bullet’s projectile after leaving the barrel. The external path is calculated using several formulas, the easiest of which is kinetic energy (Wilkinson, 1998). From the kinetic energy formulae, the energy of the bullet can be calculated by multiplying its mass with the square of the bullet’s velocity, and thereafter dividing the result by two. This procedure enables the calculation of the bullet’s energy as it leaves the muzzle. Since the drag is a factor, its value has to be calculated too. These operations are of great importance to forensic experts, as they are crucial in firearms related crimes to provide clues hence enhancing swift investigations.
For terminal analysis, yaw determines the extent of the injury. A petite, high velocity bullet, increases drag and releases more kinetic energy to its target. For more kinetic energy, a broader and heavier bullet is employed despite its ability of releasing little kinetic energy on meeting the target. Bullets with low velocity can be used effectively by redesigning them to release all their kinetic energy on the target. Through this approach, significant tissue damage is achieved for short guns.
Bullets damage tissues in three ways. First, a bullet lacerates by crushing tissues and bones. Bullets travelling with low velocity cause this form of damage. Subsequently, through cavitations, tissues are broadly wounded. This damage occurs because of the intense forward movement of the air upon the impact. Lastly, through shockwaves, the target is compressed as the bullet forges ahead. These waves are short lived and cause little destruction at low velocities. However, at higher velocities, more destruction is achieved. This impact on humans normally induces a concussive effect leading to severe neurological symptoms.
Several firearms have been reported in crime scenes (Belton, 1992). When investigating on handguns, one should consider some basic details in these scenes. The investigator should be fully aware that handguns are easily concealed and accurately used at short distances. This is the main reason why most criminals prefer short guns in crowded places. Such basic details provide insight into a crime investigation. Ballistics wounding for the case of shotguns depends on the used pellet’s type. Equally, the spread of the pellets should be given significant attention as they provide a preview on the used gun’s barrel. For example, the pellets from a short-barreled shotgun spread over a wide area. Forensic experts try to analyze these basic details to determine the bullet and firearm type used at a crime scene.
Qualifications
In Canada, for one to qualify as a forensic firearms expert, he or she must meet the required conditions (Blau, 2009). Initially, one is required to have a degree in science or criminology. The course normally lasts for 4 years. In addition, one should possess a post-secondary forensic science training, which is normally done after obtaining a diploma or first-degree course. Consequently, one should acquire an appropriate certification from forensic societies and must have worked as an understudy after graduation. However, police officers and firearms experts are given special considerations and undergo some basic courses without having to undertake the normal degree program. In addition, ballistic experts must have wide background knowledge on ammunition, crime scene search, firearms recognition, law, microscopy, and the ability to locate and train crime witnesses. The background knowledge is essential before one is allowed to work as a ballistic expert (Blau, 2009). In addition, knowledge on clerical and administration service, philosophy, theology, and counseling, will boost one’s skills in the forensic field as successful investigations require varied solutions and approaches. The background skills required in firearms related careers include collecting and organizing information, identifying related challenges, critical thinking, wise decision making and testing operations (Blau, 2009). Besides, an expert in this field is supposed to be articulate in both spoken and written language skills.
In the last decade, Canada has experience dramatic reforms in the forensic field. Authorities came up with policies and strategies that faced out incompetent experts (Anderson, 2009). These reforms conform to the countries’ forensic principles and international standards. Firearm experts are expected to apply their knowledge and skills in different crime related incidences. They are required to analyze different marks left on the firearms and thereafter work with the law enforcers in identifying the criminals. Like fingerprints, two firearms of the same make and model will produce varied marks on fired bullets and cartridges cases. By exploiting this property, forensic experts can link bullets and shell casings at the crime scene to the perpetrators of the crime. The unique markings, collected at the crime scene are screened and their images stored in the database for detailed analysis.
Strengths
Forensic firearms analysis has proved to be a vital art in several investigations departments. Through this art, several crimes have been successfully investigated and solved. In addition, events at the crime scene have been simulated using this art. In the late 1990s, Canada adopted the art of using an automated firearms imaging and comparison kit (Gardner, 2008). Since then, it has been used to analyze firearms related data. The equipment makes use of crime images collected by the experts. The images of bullets and shell casings collected at the crime scene are initially fed into in the equipment’s database. The machine then processes the images and when a match is found the examiner is can identify the make and model of the gun used in the crime. Ballistic images collected from recovered guns can similarly be used to determine if the firearm has ever been used in other crimes. Forensic scientists have used this system effectively in resolving several firearms related crimes as compared to the past. In my opinion, a lot needs to be done to improve the functionality of these machines considering that they are currently running on the old system’s technology despite the rapid advancement in crime technology. Thus, more research is necessary to bridge this ever-increasing gap.
In Ontario, ammunition serialization has greatly enhanced the investigation of various gun related crimes ((Belton, 1992). In this regard, the law requires manufacturers to stamp unique minute code on all the bullets. When one purchases the bullets, an authorized dealer records the serial number and the purchaser’s information. Subsequently, when a cartridge casket is collected from a crime scene it would be easily linked to the purchaser. As a result, forensic scientists have reported a drop in the use of guns to commit crimes. The drop was realized since many people are afraid of committing crimes using guns as they can be easily traced.
In the early 90s, the Canadian Integrated Firearms Identification Network was formed to analyze and link several firearm bullets and cartridges cases (Belton, 1992). This institution employs a central database that generates and guides the law enforcers in their duties. The database enables the analysis of bullets and cartridges throughout Canada by providing the necessary details. A forensic examiner then examines the exhibit to determine the matches. These instruments are located in laboratories in Toronto, Ottawa, Regina and Montreal (Saunders, 1987).
Forensic experts are also required to remodel the crime scene and perform chemical analysis to find out when gun was used. In this regard, forensic experts can use the acquaintance of trajectory physics to determine the distance and angle of the gunshot, subsequently locating the shooter’s location (Blau, 2009). However, there are major challenges when crimes scenes are situated at busy premises. Here, forensic experts are often forced to rush through their data hence limiting the amount of evidence needed in the court of law. Moreover, at these busy premises, curious civilians at crime scenes can easily tamper with evidence of the crime. Normally, in such situations, first hand or practical experience guarantees evidence integrity in the court of law.
Through forensic science, investigators have presented their investigations before the jury in a convincing way (Anderson, 2009). Forensic results have provided Jurors and judges with more factual data as compared to the information relayed by eyewitness. Consequently, forensics’ policies and its legal standards have considerably benefited the community (Anderson, 2009). These standards have led to the successful investigation of various crimes committed in the society and with the help of other law enforcers the suspects apprehended and judged. Moreover, those wrongfully convicted have received justice when crime scenes investigations fail to link them to the alleged crime.
Weakness
However, firearms can equally be challenged in the court of law. This relies on the fact that the marks left on the firearms must not only be unique, but must prove to be reproducible. Therefore, the full assessment of these firearms requires cautious attention to reveal the hidden evidence. Although guns leave behind substantial evidence, there is no scientifically proven method in forensic science that is able to point out the specific gun used in the production of evidence. Attorneys in Canada have often used this argument to build defenses in several instances. In some cases, wrongful convictions have resulted due to errors committed by forensic experts. These errors usually occur during laboratory analysis. In Canada, the errors have contributed to 63% of all wrongful convictions (Anderson, 2009). In my opinion, this high percentage of wrongful convictions shows how our forensic experts are not competent enough as perceived by the public. Another weakness in forensic science is the false and misleading evidence provided by the forensic experts. This is due the fact that most forensic procedures are executed without consulting other relevant scientific communities and research laboratories (Gardner, 2008). If such flaws are revealed to the public, the forensic science image will be greatly tainted. Consequently, there are some flawed findings presented in the court of law by some forensic experts. Such an occurrence is evident when the evidence presented has been exaggerated or flawed to benefit some individuals. For instance, the JKF investigations in the US showed that the finding reports were seriously flawed (Genge, 2002). The forensic experts in this case were reluctant to provide the necessary assistance. As a result, these weaknesses have impacted negatively on the whole forensic field despite the fact that the mistakes are made by a few rogue forensics who do not adhere to the required procedures.
However, there are several setbacks undermining the process of firearms investigation (Anderson, 2009). First, the creation of several law schools has led to the creation of innocence groups. During the process of their investigations, these law experts compromise on forensic evidence as they try to disapprove the findings. The media has also undermined the image of forensics. Due to the media’s limited understanding on this field, they end up publishing non-investigated findings, which misinform the public.
Finally, among these setbacks, is the role that the TV plays. To common people most forensic knowledge originates from TV’S shows. This perception has also affected the jurors to think that, the lab results are more complicated for forensic experts. In my opinion, most of the TV shows have encouraged unrealistic and biased anticipations in firearms related sciences. To most viewers, forensic firearms analysis is all about counting the bullets holes and cartridges at the crime scene. This is a biased view as forensic investigations are technical and structured contrary to their opinions. All these factors provide negative opinions on forensic sciences and may eventually weaken several convictions and erode the public sector’s confidence in law enforcement departments.
Forensic personnel have also undermined the success in this field. For instance, some of the forensic laboratory’s employees are not scientist in that they only possess a diploma the compulsory requisite for employment (Anderson, 2009). In some cases, the forensic personnel are unqualified in that during the employment process they presented forged academic credentials (Anderson, 2009). Such technicians and investigators’ reports may illustrate why our current court system still questions the validity of forensic investigations. Similarly, most of the forensic labs are associated with police departments. These police units main concern is the clearance of unsolved cases and securing conviction. In this regard, the police may reveal their suspicious views about the suspects to laboratory technicians before the analysis of the evidence. As a result, the laboratory personnel’s analysis of the evidence is prejudiced. Furthermore, some forensic experts, for personal reasons, manipulate their laboratory results (Anderson, 2009). Moreover, some errors occur because some forensic laboratories are understaffed. In this regard, workers are presented with excessive workload compromising their efficiency. Besides, some laboratory workers do not follow the procedures stated in the lab protocols. Such incidences significantly undermine the effectiveness of forensic science.
Case cited
In the U.S, firearm tests on one of the rifles found in a car suspected to have been involved in shooting incidences, linked the weapon to 3 out of the 14 shootings witnessed previously in the year 2002 ( Ferguson, 2006 ). In this case, forensic experts, through their analysis, significantly assisted law enforcers in apprehending the suspect. After several forensic examinations, the forensic experts linked the incident to more suspects. In my opinion, the law enforcers delayed in arresting the suspects despite the numerous forensic evidences provided by the investigators linking the suspects to the murders. In addition, the forensic investigators in this case did a spectacular job since they proved beyond doubt in the court of law that the suspects were guilty as charged. However, there were three incidences where the lack of enough evidence compromised the trials of some of the crimes.
Future implications
For the last decade, there have been numerous legal challenges encountered by forensic experts. These challenges were enhance by the usual practice of expecting firearms analysis to be done like a DNA analysis (Kipper, 2010). Nonetheless, the future seems promising, as these challenges would be tackled effectively. In the past, there are a few instances where court rulings contradicted the firearms experts’ evidences by questioning their integrity. In such a case, the prosecutor lacked the suitable knowledge in firearms. In my opinion, to avoid such incidence in the future, prosecutors knowledgeable in forensic sciences should be allowed to preside over firearms related crimes. Currently, numerous forensic laboratories in Canada have become accredited to ISO standards (Kipper, 2010). These laboratories will enhance proper investigations in DNA and fingerprints forensics hence increasing the handling capacity of crimes. This will also lead to the reduction of time spent on matching and linking forensic evidence. Similarly, through these laboratories, research will be improved across the forensic community (Kipper, 2010). Furthermore, there will be ample time for the examiners to scrutinize the results before their use in trial. According to CIBIN, several police officers across Canada are in possession of firearms that have not been entered into their database systems (Kipper, 2010). For future safety, police officers are encouraged to contact the nearest forensic lab to analyze their bullets and cartridges. This will benefit to all in the long run since these firearms may end up in the wrong hands.
With the continuous development in computer assisted firearms identification, future forensics will benefit from the reduction of the time spent in identity matching (Blum, 2010). If appropriately used, it will turn the current CBIN into a valuable investigative organization. However, an appropriate scientific approach is required to improve the reliability of this database. Currently, these technologies are quite costly. Designers should major on manufacturing cost effective technologies to enhance forensics in the future. Similarly, the designers should prioritize on instruments’ reliability, precision and safety in their design process. The current database systems are design to tackle traditional task related to firearms. However, modern technologies have tilted several operational ways of using guns hence the need for an updated database (Kipper, 2010). With more funded research, better-précised instruments will be developed in the firearms field to facilitate accurate investigations. Moreover, as many students graduate in forensic sciences, more workforces will be available hence increasing and facilitating effective investigation. This workforce will bring the innovation needed in forensic science as they are more technologically informed compared to the current workforce.
References
Anderson, D., & Anderson, B. (2009). Manufacturing guilt: wrongful convictions in Canada (2nd ed.). Black Point, N.S.: Fernwood.
Belton, J. A. (1992). Cooey firearms made in Canada, 1919-1979: the H.W. Cooey Machine & Arms Co., Winchester-Western (Canada) Ltd., Winchester-Cooey. Alexandria Bay, N.Y.: Museum Restoration Service.
Blau, S., & Ubelaker, D. H. (2009). Handbook of forensic anthropology and archaeology. Walnut Creek, Calif.: Left Coast Press.
Blum, D. (2010). The poisoner’s handbook: murder and the birth of forensic medicine in Jazz Age New York. New York: Penguin Press.
Carper, K. L. (2000). Forensic engineering (2nd ed.). Boca Raton, FL: CRC Press.
Ferguson, A. (2006). The Christopher killer: a forensic mystery. New York: Viking/Sleuth.
Gardner, R. (2008). Forensic science projects with a crime lab you can build. Berkeley Heights, NJ: Enslow.
Genge, N. (2002). The forensic casebook: the science of crime scene investigation. New York: Ballantine Books.
Kipper, G., & Liles, S. (2010). Virtualization And Forensics a Digital Forensic Investigator’S Guide To Virtual Environments.. New York, N.Y.: Elsevier Science.
Saunders, G. (1987). History of the Royal Canadian Mounted Police LaboratoSystem.
The RCMP Labs , 49(11). Web.
Wilkinson, F. (1998). Firearms. London: Camden House Books.
Forensic toxicology is the study of all elements of toxins that have legal repercussions. The use of forensic toxicology in law enforcement has resulted in a significant decline in the number of chemical- and drug-related deaths and accidents. Forensic toxicology is applied in many areas of law including: postmortem drug testing, workplace drug testing and investigation of illegal materials (Becker, 2009). Postmortem drug testing involves the investigation of death to establish whether the cause of death or one of the contributing factors of the death was drugs (Saferstein, 2006). Fatalities as a result of unintentional or premeditated drug overdose are many. On the other hand, there are some cases of death that are homicidal in nature. Forensic toxicology helps in establishing the nature of drug-related death.
The second application of forensic toxicology is in the workplace drug testing. This involves the assessment of biofluids from workers and candidates for drug content. The law normally permits unscheduled drug testing for workers in specific occupations such as security agents. In such occupations, the law puts the public security above the privacy rights of the employees concerned. Such employees may also be required to provide specimens to be tested for drugs if they seem to be weakened by the consequences of alcohol or other illegal drugs. The majority of the employees do not go through mandatory forensic toxicology testing. However, job applicants are often mandated to go through drug testing as a pre-requisite for employment. The logic behind the drug-free employment condition is based on research studies which have shown that individuals who use illicit drugs are usually unreliable and unproductive at work (Becker, 2009).
The evaluation of contraband materials is the third application of forensic toxicology. As part of the nation-wide effort to halt drug abuse, laboratory support is needed by police agencies to establish that a confiscated material is indeed a forbidden material. For instance, if cocaine is found in the possession of a suspect, a conviction for illegal possession necessitates that the material be scientifically proven to be actually cocaine. Such specifications are established by police agencies in the field using rapid, transportable testing kits. The success of forensic toxicology depends to a large extent on the forensic toxicologist who plays significant roles not only in the analysis of specimens but also in interpretation of the results (Becker, 2009).
The Role of the Forensic Toxicologist
The major role of the forensic pathologist is to elaborate the cause of each death that is under his or her jurisdiction and to establish the nature of the death, that is, if it was unintentional, suicidal or homicidal (Levinson, 2002). The forensic toxicologist immeasurably assists the forensic pathologist in carrying out comprehensive analyses of a wide range of toxins. Other roles of the forensic toxicologist include the identification, analysis and study of the effects of drugs, poisonous, and environmental chemicals on the human body. Usually, toxicologists are mandated to establish the existence of unanticipated chemical substances in body fluids or tissues and to establish the amounts of that substance in the sample. Toxicologists are especially important in dealing with driving under the influence (DUI) incidents as well as other civil and criminal cases that involve the ingestion of toxic substances (Lee & Harris, 2006). The significant decline in the number of poisoning incidents over the last one and half centuries has been attributed to the ability of the forensic investigators to establish poisons in corpses.
Specimen Collection in Forensic Toxicology
Blood
Blood is the most crucial biofluid in forensic toxicology involving cadavers. This is because chemicals found in blood have a higher probability of having positive correlations with the lethal outcome as compared to other biofluids. Two blood samples are usually collected, one from the heart and the other from a peripheral location. The approximate volume of blood collected ranges from 50 to 100 milliliters (Goldfrank & Flomenbaum, 2006).
Urine
In work-related drug assessment, urine has better outcomes than blood because the former can be collected in larger volumes. In addition, urine collection process does not involve any puncture of veins. One possible disadvantage of urine is that the relationship between the amount of drug in urine and the drug outcome is normally weak. Nevertheless, the rationale behind pre-employment screening is merely to establish if the individual has been actively engaged in consumption of illicit drug and urine is adequate in addressing this question. Urine is also used investigations of cadavers because some chemicals found in urine are in higher amounts than they could be in blood. The test of blood alone could therefore lead to negative results.
Gastric contents
The evaluation of gastric contents is advantageous in cases where a person died suddenly and was found to have large amounts of toxic substances in the stomach. If the person died by suicide, the presence of large amounts of toxins in the stomach may make it clearer (Goldfrank & Flomenbaum, 2006).
Vitreous humor
Vitreous humor is collected after a person dies. It is found in the eye which does not decay because it is a peripheral organ. The evaluation of the vitreous humor may be beneficial in ascertaining the time of death.
Bile and liver
Liver is the organ that is heavily involved in drug metabolism. It is probable to have huge amounts of a majority of the drugs and may occasionally allow the identification of a substance that led to death even if the substance is not present in blood. Bile drains from the liver and contains rich amounts of some types of drugs such as opiates (Goldfrank & Flomenbaum, 2006).
Analysis of Toxicology Specimens
The evaluation of organ tissue and biological fluids is hampered by the reaction of chemicals that takes place as cadavers decompose. As a result, it is usually recommended that the autopsy and testing of specimens be carried out immediately a person dies (James & Nordby, 2005). Forensic toxicology is usually carried out through a number of tests such as immunoassay test and gas chromatography-mass spectrometry (GC-MS). This latter test makes use of the difference in chemical characteristics between different parts of a mixture to separate the molecules (James & Nordby, 2005). The molecules have different retention times of getting out of the gas chromatography, and every compound separated through this manner enters the mass spectrometer. The mass spectrometer then divides each molecule into charged portions in accordance with their mass. The GC-MS then makes a comparison between the spectra produced during analysis and its stored database until a match is found (Girard, 2008).
Gas chromatography has been used successfully in solving deaths that seemed a mystery to forensic scientists. For instance, one case involved a drug-facilitated sexual assault of a 13-year-old girl. Initial investigations failed to solve the mystery because no visible signs of physical harm, strangulation, rape or violence were seen. Using GC, however, the forensic toxicologist found that the young victim had been sexually assaulted using chloroform whose concentration in the blood was found to be 833.9 mg/l. The outcome of this case inspired the need to search for poisonous substances in such seemingly mysterious cases (Gaillard, Masson-Seyer, Giroud, Roussot & Prevosto, 2006).
Interpretation of Toxicological Information
After the analysis, the forensic toxicologist assembles the findings, studies them, and then determines the actual factor that led to the death. The inference made from the data analysis is the most challenging work of toxicologists. They must establish the manner in which the drug was ingested, the quantity of the administered drug, and whether the administered drug was enough to lead to the death of the person. To establish the route of the poison administration, the toxicologist makes a comparison of the amounts of drug present in the specimens. In general, the highest amount of poison will be found at the point of entrance into the body. If this concentration is found in the gastro-intestinal tract or the liver, it implies that the poison was administered orally. Illicit drugs such as cocaine, heroin and phencyclidine are usually taken through smoking. If the highest concentration of such drugs is found in the lungs than in other body organs, it implies that they were inhaled. For drugs that were administered intravenously, the highest concentration would be found close to the place where the drug was injected (Goldfrank & Flomenbaum, 2006).
In making interpretation of findings, the toxicologist must take caution of the possibility of administration of medical treatment such as blood and plasma transfusions just before the death. This is because such treatments may dilute or flush out poisons. The finding of poison in any body organ does not necessarily mean that it was the cause of death. To establish its lethal impact, the toxicologist must conduct an analysis of other specimens to confirm that the poison was indeed absorbed and then transported to other body organs (Girard, 2008). Poisoning from very strong acids is however exempted from this rule. This is because strong acids such as sulfuric acid destroy tissues on contact and lead to severe bleeding and shock.
Alcohol and the Law
Laws against “drinking and driving” have been in existence since the 1800s. Nevertheless, drinking under the influence of alcohol became a public issue in 1933-1934. Indiana became the first state in 1939 to pass a “drunk driver” law. Blood alcohol concentration was used to determine the sobriety of a person. The “drinking and driving” issue has attracted the attention of many scholars who have been interested in showing how alcohol affects the skills needed for navigating a car, for instance, clear vision and balanced hand-eye coordination (Saferstein, 2006).
Alcohol metabolism
Alcohol passes from the mouth to the small intestine through the esophagus and the stomach. As it travels, it is absorbed into the bloodstream mainly from the stomach and the small intestine (Wurst et al., 2006). This absorption generates the blood alcohol concentration. Once it reaches the bloodstream, the alcohol is transported to the brain where the concentration of alcohol is equal to the BAC. The rate at which alcohol is absorbed into the bloodstream is affected by many factors such as “the rate of gastric emptying, the presence of food in the stomach, the concentration of the ethyl alcohol taken in, the type of alcohol-containing beverage and the rate at which the alcohol is ingested,” (Girard, 2008, p. 313). Even though alcohol enters the body through absorption, the process is slow and takes a long time to distribute the alcohol throughout the body. Rapid distribution of alcohol is facilitated as the ethyl alcohol traverses into the internal membranes of the cells in addition to water. Water hastens the distribution of alcohol throughout the body’s tissues. As a result, the amount of ethyl alcohol in a tissue is directly proportional to the water content found in that tissue (Fracasso, Brinkmann, Beike & Pfeiffer, 2008).
Testing for alcohol
Law enforcement officers test for alcohol among drivers using various testing instruments the most common of which is the Breathalyzer. The Breathalyzer measures the concentration of alcohol in the suspect’s breath indirectly by measuring the absorption of light by potassium dichromate prior to and after reacting with alcohol (Saferstein, 2006). As the potassium dichromate continues to react with alcohol in the Breathalyzer, the amount of the potassium dichromate falls in the suspect’s sample. On the other hand, the amount of light absorbed by potassium dichromate falls proportionally to the level of alcohol in the sample. The comparison between the sample of the suspect and the reference one leads to an electric current that forces the needle of the Breathalyzer to move from its initial resting place. The operator then moves the needle back to its resting place and reads the amount of alcohol recorded.
One major disadvantage of the Breathalyzer is that it consumes chemicals. Therefore, the test administering officer should continuously supply the Breathalyzer with adequate quantities of fresh chemical reagents. Failure to take this precaution may make the evidence inadmissible in court because defense lawyers may argue that the readings were false due to the use of outdated chemicals (Girard, 2008). Besides the use of testing kits, alcohol consumption can also be tested through the analysis of blood using the gas chromatography method. The disadvantage of using this method on living beings is the need to draw a blood sample from them. The method can also be used to test for alcohol content on corpses. The process of blood collection from a suspect first begins by disinfecting the skin with a non-alcoholic disinfectant, for instance, Betadine. This prevents the suspect from alleging that a high BAC level was influenced by the disinfectant. The collected blood sample is then kept in a refrigerator in an airtight container. Lack of refrigeration may render the BAC level to be abnormally low, whereas the failure of properly preserving the blood sample may render the reported BAC to be abnormally high (Girard, 2008).
In sum, forensic toxicology is an important field. It helps in solving so many criminal and civil cases which would otherwise seem a puzzle to the law enforcement authorities. Although widely used in alcohol-related incidents, other substances such as illicit drugs and poisons are also identified effectively using forensic toxicology. Despite its great potential in identification of chemical substances, care must be taken during the interpretation of findings because of the existence of many possibilities of the cause of death. Nonetheless, forensic toxicology has had profound effects in solving chemical-related cases which have in turn minimized the occurrence of such incidents.
Reference
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Camenson, B. (2008). Opportunities in forensic science. New York: McGraw-Hill Companies, Inc.
Fracasso, T., Brinkmann, B., Beike, J., & Pfeiffer, H. (2008). Clotted blood as a sign of alcohol intoxication: a retrospective study. International Journal of Legal Medicine, 122, 157-161.
Gaillard, Y., Masson-Seyer, M., Giroud, M., Roussot, J., & Prevosto, J. (2006). A case of drug-facilitated sexual assault leading to death by chloroform poisoning. International Journal of Legal Medicine, 120, 241-245.
Girard, J. (2008). Criminalistics: Forensic Science and crime. Sudbury, MA: Jones and Bartlett Publishers.
Goldfrank, L., & Flomenbaum, N. (2006). Goldfrank’s toxicologic emergencies. New York: McGraw-Hill Companies, Inc.
James, S., & Nordby, J. (2005). Forensic science: an introduction to scientific and investigative techniques. Boca Raton, Florida: CRC Press.
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Wurst, F., Yegles, M., Alling, C., Aradottir, S., Dierkes, J., Wiesbeck, G., et al. (2006). Measurement of direct ethanol metabolites in a case of a former driving under the influence (DUI) of alcohol offender, now claiming abstinence. International Journal of Legal Medicine, 122, 235-239.