Bite Mark Bacteria May Help Forensic Scientists Identify People

Bite Mark Bacteria May Help Forensic Scientists Identify People

Research conducted at the Sir John Walsh Research Institute in the University of Otago’s School of Dentistry in New Zealand suggests that oral bacteria left from bite marks on human skin (common among victims of sexual assault) may help forensic scientists identify perpetrators. Identifying individuals from bite marks alone is difficult because tooth impressions on the skin do not vary tremendously in shape or defining characteristics, and this is particularly problematic in developing countries where dental records may be scarce. But because each person’s oral bacteria are marked with his or her specific genotypes, Geoffrey Tomkins BSc, DipSci, PhD, molecular microbiologist and senior researcher at the university, suggests they may be helpful for identification purposes.

One problem is that oral bacteria quickly die after leaving the mouth, which narrows the window of opportunity needed for use in identification. University of Otago student Lillian Hsu, however, suggests that DNA from dead streptococci—a bacterial species commonly found in the oral cavity—can be used to create DNA profiles, an important tool in forensic identification. This technique is only in its beginning stages, and additional research is under way to see whether the method has any merit.