Challenges Facing Us in DNA Analysis from Human Hair Samples: A Review

Human hair is a valuable tool in criminology, aiding in population studies through statistics and DNA analysis. It's easily identifiable at crime scenes, often clinging to clothing, carpets, and various surfaces, including animal fur, through a process known as secondary transfer. Forensic analysis of hair evidence serves several purposes; it can help establish the possibility of a connection between a suspect and a crime scene or between a suspect and a victim. It can demonstrate that there is no evidence linking the perpetrator to the crime scene or the suspect to the victim. While microscopic hair analysis cannot definitively identify a specific individual as the source of the hair, it does provide a solid basis for association. The wealth of macroscopic and microscopic details available in hair examination can also provide strong evidence for the defense. To understand the challenges of conducting DNA tests on hair, it's essential to study hair structure and composition. DNA in hair is not evenly distributed throughout every part of the hair; it exists in both nuclear and mitochondrial forms.