This paper examines the role of hair evidence in forensic science, focusing on its application in criminal investigations involving homicide and violent crime. It discusses why forensic investigators consider hair a valuable form of trace evidence, covering proper collection procedures, the analytical capabilities of hair examination, and the limitations of hair as a class characteristic rather than a definitive identifier. The paper also addresses DNA extraction from hair follicles, the use of hair to establish suspect connections, and the importance of maintaining evidence integrity throughout the collection and processing chain to ensure admissibility in court.
The paper demonstrates the use of structured legal-analytical reasoning applied to a scientific topic. By framing the discussion around Issue, Rule, and Analysis, the author shows how forensic evidence can be evaluated both scientifically and within a judicial admissibility context — a cross-disciplinary technique valuable in forensic science writing.
The paper opens with a brief introduction establishing the relevance of hair evidence, followed by an "Issue" section questioning its evidentiary value. A "Rule" section describes established forensic procedures for collection and examination, and an "Analysis" section covers the biological and genetic properties of hair. A short conclusion ties together the investigative and legal implications of hair evidence.
Hair evidence has been utilized in high-profile cases involving homicide and violent robbery. This paper highlights the real issues surrounding the use of hair as evidence, evidence processing procedures, the viability of obtaining DNA from hair that is admissible in forensic evidence presentation, and the guiding principles for using crime scene evidence such as hair and other bodily materials.
Hair evidence plays central roles in criminal investigations, which is why many forensic investigators consider it invaluable. A thorough examination of hair evidence can often indicate the race of the subject. Hair samples can also be compared with one another to determine whether multiple individuals were present at a scene or whether evidence originated from a single subject — a concept referred to as common origin of evidence. Hair gives forensic personnel an advantage in that multiple samples can often be collected within the same crime scene.
Hair evidence must be collected using tweezers, kept in a paper bindle or coin envelope, and then stored safely in a larger, properly labelled envelope. It is important to handle hair evidence with care. If hair is embedded in dried blood, glass, metal, or similar objects, it should never be removed from those objects but instead left intact and transported carefully to the processing laboratory.
Hair is currently used as evidence in a wide variety of crimes. A key question is whether hair truly constitutes vital evidence across such a broad range of criminal cases. Hair is an important resource in forensic science and is responsible for providing valuable clues to the identity of an attacker or assailant. Like other fibers, hair specimens are understood in forensic research as class characteristics — meaning hair may share enough similar properties with a known sample to be considered consistent, but it cannot definitively be declared a perfect match.
The discovery of hair on a victim's body or on the clothing of an assault victim can in most cases be used to help determine the race and sex of the source individual. While hair samples can be used to exclude a suspect, they are best characterized as contributing evidence rather than conclusive proof. Hair can also be used to extract DNA that may then be used for comparison purposes (Ramsland, 2010).
Hair evidence is useful in establishing the scope of a particular crime. It can help place a perpetrator at a crime scene and connect a suspect to a weapon. It is also used to support witness statements and to connect related locations such as a dump site, an abduction area, or a vehicle used in the commission of a crime.
However, it is important to ensure that the integrity of hair evidence is maintained and that due process is followed in its storage and processing. Failure to observe proper procedures may render all investigative effort useless if the evidence is successfully challenged by attorneys in court.
Ramsland, K. (2010). Hair evidence analysis. Retrieved July 7, 2014, from www.crimelibrary.com/criminal_mind/forensics/trace/5.html
Claridge, J. (2014). Hair and fibres in forensics. Retrieved July 7, 2014, from http://www.exploreforensics.co.uk/hair-and-fibres.html
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