Characteristics of Cut Head Hair: An Evidence in Criminal Investigations

Abstract

One hot news occurred in Thailand one year ago was a 3-year-old girl was murdered and only a number of hair strands were found near her body and likely cut by a knife. Later some cut hairs were found at the cloth of the suspect. In this study, the authors would like to match the hairs found at the crime scene with the hair found at the suspect’s ware. However, the real hairs obtained from such case could not be used for this study. Therefore, the head-hair samples were cut from one author of this study. Then, the structural properties including the size, cutting angle and surface morphology of the cut hairs were investigated using scanning electron microscopy. The results on the cutting of two hair strands and five hair strands at the same time showed that the cut hairs could be verified that they came from the same person. Furthermore, if a number of cut hairs were found at the crime scene and some hairs were found at the suspect’s ware, such as at the cloth or in the car, by the method used in this study it can also verify that all hairs were cut at the same time and came from the same person.