Forensic Serology and Its Key Aspects in Investigating Crimes

NB: We do not resell your papers. Upon ordering, we do an original paper exclusively for you.

NB: All your data is kept safe from the public.

Modern technology in the field of science has yet again proved to be vital in investigating crimes. The discoveries that have been made over the years about the components of blood are now being widely used by the police to ascertain the individual that may be responsible for involvement in a crime. Such investigations are important in cases that involve murder and rape. Following such laboratory tests, many cases have had to be dismissed due to the fact that the suspected victims that were presented were proved to be innocent with the completion of the tests. The main shortcoming of this investigation is that, it is not possible to prove the guilty and only the innocent are eliminated.

Forensic serology is a study of the body fluids like blood and saliva for criminal investigations. Such investigations are usually done in cases that involve murder and rape to determine the exact criminal. Compared to other investigatory measures that may be used, body fluids will provide concrete evidence of the assailant. This is due to the fact that, body fluids differ from one individual to another. The use of forensic serology to investigate crime victims became of importance after it was discovered that, many innocent victims were prosecuted for the crimes they were not guilty of.

Dr. Karl Land Steiner was awarded in 1930 following his investigation that human blood could be divided into four major types. This groups are; O, A, B and AB (Stuart, 2005). As much as it is not easy to determine if certain blood came from a particular individual, it is possible to recognize that, a certain blood sample did not come from a certain person. To enhance such investigations, new antibodies have been discovered in the blood. In these discoveries, it was found out that, an antigen named Kell is found among the white population while the Duffy antigen is absent.

It has been possible to distinguish between human bloods from that of other animals. Human blood can also be investigated to determine the gender and age of the victim. In carrying out investigations, the shape and pattern of the blood assist in determining the circumstances of the murder. Other evidences to ascertain the assailant include; dried blood stains on the clothes of the suspect, the scene of the crime, the weapons used and struggle evidences. A simple drop of blood when critically analyzed can provide a lot of information concerning a case.

When distinguishing between blood stains from other fruit and dye stains, the Kastle-Meyer test is used. In this test, when a solution of phenolphthalein comes in contact with any blood stain, it turns pink. In determining whether the blood under question is of a human being or an animal, the precipitin test is used. Due to the fact that blood of different species contains different proteins, a distinction can be made. The proteins in the blood of a certain species cannot be accepted by the proteins of another species. This is usually due to the presence of antibodies in the blood that are responsible for fighting and resisting any foreign matter.

The serum that is used for the precipitin test is obtained from the rabbit. This is because; the antibodies of a rabbit were found to destroy human blood that came into contact with it. A small potion of this antihuman serum is usually dropped into the blood of the suspect, if the blood is of human nature, it will precipitate its protein. The criminal investigation laboratories are equipped with different anti-sera for the most common animals to enhance their investigations and rule out any false evidences. This test was developed by a German scientist known as Uhlenbuth in 1901 from whom the name of the test was derived.

There is usually a difference between a fresh blood stain and an old one. A fresh one will always appear red while an old one drastically changes its color to brown. Due to this, the peroxide tests take a much longer time to determine the origin of an old blood stain compared to a fresher one. In determining the gender from which the blood stain originated, two British scientists discovered that the female tissues contain a distinctive drumstick structure in the cells nuclei that is rarely found in males. The structure was named Barr after the scientists who discovered it in 1949. The structure is mostly found in the epithelial cells of the mouth and within the white blood cells. The number of chromosomes in a Barr body differs significantly in males and females, which form the basis of their use in investigating whether the blood stains are of male or female being. (Saferstein, 2001)

Blood stains on the weapon used for murder and on the clothes of the suspect are critical evidences that can be extensively investigated to prove the suspect. They can also be used to determine whether the death was violent or not. Blood grouping is a technology that can be used to determine whether there was contact between the victim and the suspect (Ronald, 2008). Different blood groups are distinguished as either A, B or O due to a substance called agglutinate that is present in the red blood cells. Blood group A contains a agglutinate, blood group B has B agglutinate, AB has both A and B agglutinates and O contains none of them.

In 1927, more factors were discovered to occur among the blood of human population that was distributed in certain specific proportions. These factors contributed to the P factor and they were identified as M, N, and MN. This was followed by the Rhesus factor in 1940. It is through the knowledge of these blood groups that, it was also discovered they are hereditary and last for a life time. This was a boost to the criminal investigation department. Even though forensic serologists are able to group different blood groups, it is not yet possible to determine from which individual a blood portion was obtained.

Therefore, the aim of using such investigations to try suspects is to eliminate the individuals that are proven innocent. Once the innocent ones are eliminated, the investigation process is made easier and other possible evidences are used to confirm the suspect.

In carrying out a blood test, the collected sample is placed in a saline solution and a tiny extract mixed with solutions of potassium hydroxide and phenolphthalein with hydrogen peroxide and powdered zinc. The sample will be proved to be blood if it shows a pink color after the experiment. When this investigation is completed, an antiserum from an animal is used to identify whether the blood is of human nature or from an animal. Various tests may also be carried where there is necessity to determine the race and gender of the suspected blood sample.

In determining the blood groups of different races, the international forensic serologist also discovered that, the rhesus antigen V is mostly present among the West African Negroes. The Duffy phenotype was also discovered to manifest in large percentages among the West Africans (Saferstein, 2001). The kell antigen is common with the white race and Diego positives in Caribe Indians, the Chinese and the Japanese. Such investigations may be important where a crime involves suspects from different races.

Case study on forensic investigation

In June 1994, the Beverly Hills residents woke up to a shocking scene where the body Nicole and her friend Goldman were found murdered next to their door. On notification, the police arrived and started their investigations. A left hand glove that was stained with blood was found. The main suspect was Nicole’s ex husband, Simpson who was staying nearby. Although he had taken a night flight to Chicago, they noticed a trail of blood over his car to the house where the second glove was found. He was immediately contacted in Chicago and took the next flight back. He had a bandaged hand, which he related to an injury he had sustained sometimes back. All the investigations were done and evidences revealed that, he was the suspected murderer. Despite all this, the case was dismissed after Simpson’s lawyer claimed that one of the investigating officers was a racist and had all the time to set up the scene. There were also large number of mistakes like unnoticed clues and unsterilized swabbing methods. Simpson was declared innocent after nine months of trial.

Forensic serology has played a big role in eliminating suspects that were wrongly accused of being involved in a certain crime. There have been several cases where the possible evidence that were done led to the arrest of a certain suspect who although may be innocent, is not in the capacity to prove his or her innocence to the court. It is usually difficult to prove the suspect that is guilty in cases involving murder. This is usually because; the main witness who is the deceased is not in position to speak out. Most of the physical investigations that may be carried out may be misleading because; the guilty individual will do all that he can to manipulate the available evidences against him.

There have also been cases in which the victim is unable to identify the assailant due to the circumstances in which the offence was done. In most rape cases, the victim may be blind folded making it difficult to know the assailant. Using the body fluids found on the victim’s body and clothing, the investigations is possible. The first step that is taken in such situations is to gather the possible suspects using physical means. Once this is done, the innocent ones are eliminated by forensic serology. From this stage, the investigations are narrowed down and by the use of other technologies the suspect will be proved guilty of the offence or not.

In conclusion, it is clear that the biological means of investigating criminals provides a strong basis of setting the innocent suspects free. This has proved to be a major step in the criminal investigation department in which manipulation is eliminated. With continuous study in the field, more discoveries may be made on the human anatomy that will be of great help to the criminal investigation. (Saferstein, 2001).

References

Saferstein R. (2001): Criminalistics: Prentice Hall pp. 37-43

Stuart H. (2005): Forensic science: CRC Press pp. 23-28

Ronald F. (2008): Criminal Investigation: Jones & Bartlett Publishers pp. 19-24

Click Here To Order Now!

Forensic Serology and Its Key Aspects in Investigating Crimes

Do you need this or any other assignment done for you from scratch?

We have qualified writers to help you.

We assure you a quality paper that is 100% free from plagiarism and AI.

You can choose either format of your choice ( Apa, Mla, Havard, Chicago, or any other)