Updated on 19 October, 2021
Did you know that the FBI is using DNA evidence to solve crimes? DNA evidence, short for DNA from samples of living things, is one of the most powerful tools ever developed for the investigator. By determining a person's DNA match to another sample, forensic scientists are able to identify and connect a living person to an unidentified suspect. Crime scene evidence and dental records can often be used to positively identify a person through their DNA, making it one of the most powerful methods of crime scene investigation. It is a relatively new form of technology that has helped solve many cases.
The FBI lab uses the DNA method to determine if the testimony of witnesses is reliable. DNA testing from known or unknown sources is highly specific, which means that even very small differences in genetic code between living people can vastly alter the results. For example, if witnesses report seeing a man with long brown hair that is slightly darker than their usual brown hair at the crime scene, and then the man has a much lighter hair color (somewhat gray) after the incident, the probability that they are seeing the victim is high. The forensic science expert witness will test the DNA to confirm this conclusion, proving beyond doubt that the man in question is indeed guilty.
In addition to linking known criminals to known events using their DNA, the FBI lab also uses a different form of DNA testing known as molecular fingerprinting. This technique has recently been applied to the unsolved mystery of the serial killer known as the Green River Killer. Because his body was discovered in a dumpster behind a public park, many people were sure that he was involved in such a crime. However, despite the many death clues found at the scene, no solid DNA evidence tying him to the crime has ever been found.
A team of experts from the FBI, including biological scientists, took a fresh look at this crime 20 years after it occurred. Through an expert analysis of the victims, dental records, and more, the scientists were able to determine that the victim in fact had a definite type of genetic disease that left a distinct hair pattern. Despite the lack of physical evidence linking the suspect to the crime, the results of the DNA testing were conclusively in his favor. Because the microscopic hair sample did not contain the necessary amounts of DNA to positively identify him, the team was not able to make a definitive determination. Because DNA testing has been so effective in linking perpetrators to known crimes, this method of criminal justice testimony has become increasingly more useful for both the defense and the prosecution.
Another example of how a DNA test can be crucial to a legal case can be seen in the case of OJ Simpson. Simpson was tried and ultimately convicted of murder for the drowning of his ex-wife and subsequent murder of her friend Ronald Goldman. The prosecution had relied on the testimony of a private eye who had obtained physical proof that Simpson had in fact been present when the murder occurred. DNA testing ultimately proved that Simpson was not involved in the crime, as his sample was found a few days after the murder by a cleaning lady who had taken part in the memorial ritual that killed Goldman.
A third example is that of Jon Benethel. The entertainer was charged with the attempted murder of his own brother, Ariel. The prosecution presented a forensic scientist's testimony in which he presented pictures of the alleged crime scene and latent finger prints that were too small to be useful in establishing a link between the suspect and the scene. Jon Benethel's attorney retained a private detective to conduct his own microscopic hair analysis to determine whether there was any DNA present. The results ultimately cleared Benethel of any connection to the crime.
As these examples demonstrate, the value of microscopic hair analysis is not only limited to establishing a link between two suspects in a criminal case, but can also be used to eliminate one. While there are many variables that play into the reliability of a forensic science testimony, the results of microscopic hair analysis can be exceptionally accurate in determining innocence or guilt. In addition to these variables, the process of collecting hair samples from crime scenes and examining them under a microscope provides unparalleled opportunities for experts to educate the public about the importance of maintaining a clean and law-abiding society.
In conclusion, the value of a Dna Hair Test cannot be overemphasized. Whether it is performed by a medical examiner or a private detective, a hair sample from a crime scene can provide overwhelming evidence in either cases or both. Hair samples that contain DNA present a good opportunity for the identification of unknown biological markers. On the other hand, hair samples that do not contain DNA can provide strong evidence against a suspect. The key is for the examiner to determine which type of sample is more reliable based on the circumstances of the collection, processing, and analysis.