Forensic genetic genealogy: law enforcement’s new frontier

Today’s cover story looks at how DNA databases for tracing family trees can be used to crack cases that have long baffled police.

“Find new relatives you never knew existed through your shared DNA,’’ is the typical sales pitch from companies offering do-it-yourself test kits to trace your heritage. Many millions of people take up the offer but how many consider the skeletons that might be lurking in the family closet? We’ve heard of parentage secrets being revealed but now this huge public database of DNA samples is being used to solve crime.

Journalist David Murray tells the story of a woman in the US who, having uploaded her results to a public database, was contacted by police: her DNA had led them to identify a double murderer who happened to be her distant cousin. She calls herself a genetic witness, one of many being unwittingly thrust into criminal investigations. Police here see the potential to crack many cold cases and the technique is already being used for an important cause: to put names to some of the hundreds of unidentified remains.