Trends in the Forensic Examination of Hair

Hair is one of the most commonly encountered trace evidence of crime scenes. The cases in which it may be found as evidence vary, ranging from those involving exotic and endangered wildlife species, hunting of which has been prohibited to various homicidal and assault cases. Besides homicide, sexual assault, and rape cases, hair is common evidence in poaching and other wildlife-related cases. The forensic examination of hair can help in personal identification (from human hair) and species identification (from nonhuman hair). Conventionally, the hair examination starts with the microscopic examination which is further extended to modern analytical methods such as DNA profiling, neutron activation analysis, inductively coupled plasma-mass spectrometry, scanning electron microscopy-electron-dispersive X-ray spectroscopy, infrared spectroscopy. However, recent years have observed significant improvement in the sensitivity, reliability, and applicability of these methods. In the present review, a critical analysis of methods of hair examination has been done.