Real World CSI - Darnell Kennedy

A student who fought off an assault bit her attacker. A suspect is found with bite marks. Can the two be linked?

University of Otago Magazine, June 2010 - Nigel Zega

Researcher

Darnell Kennedy: “Recovering a biter’s DNA from a bite mark is difficult as enzymes in saliva degrade DNA. We’re working to see if we can link unique streptococcal DNA from a bite mark to the teeth of the biter.”

Background

After a biochemistry degree, Kennedy’s PhD is aimed at developing new techniques to measure the streptococci that colonise our teeth and are deposited with bite marks.

As everyone appears to harbour unique collections of Streptococci, DNA sequencing could make a match.

Kennedy is building on earlier work by dentistry students, but has access to new advanced sequencing technology. She has ethical approval for volunteers to bite themselves just hard enough to leave a mark – blood would contaminate the sample – so measurements can be taken after a few hours.

Kennedy has also had a computer programme developed to tackle the huge amount of data generated.

Initial results suggest the future for forensics is looking bright – and the student’s attacker could soon be convicted.