The transfer and change of paints in a hit-and-run motor vehicle accident

This work investigated transfer and change of paint evidences in a case of hit-and-run. Two kinds of attachments were found on the clothes of the victim and they were initially considered paint fragments from the vehicle causing the accident. Infrared spectroscopy (IR), scanning electron microscope–energy dispersive spectrometer, and Microspectrophotometry were applied for examination of paints and clothing fibers. Polyester was detected in one of the attachments and in the clothing fibers of the victim by IR. A traffic accident simulation experiment was designed and conducted to research whether the polyester attachments come from suspected vehicle paints or victim's clothing fibers. The results showed that a melt mixture of transferred paints and clothing fiber was formed after a violent collision. Because the amount of transferred paints was too low to be detectable in the mixture, the components detected by IR were mainly from clothing fibers. Thereby, we inferred that only one kind of attachment and paint fragments existed on the clothes of the victim, and the polyester attachments cannot be used to indicate the composition of suspected vehicle paint. Clothing fibers and paints are both common trace evidence in traffic accident cases, and more attention should be paid to the examination of transferred paints on clothing fibers.