What do you tell a detective who says you are genetically related to a criminal and wants to know who you think it might be? So asks the St. Louis Post-Dispatch, saying that investigators may soon routinely trace suspects using their relatives’ DNA – a technique that could solve more crimes but that causes critics to fear for innocent people’s privacy. A crime lab worker scouring databases for a match to an unknown suspect’s DNA can sometimes detect a profile with enough similar traits that it might belong to a close relative.
Once police have a family in their cross hairs, they can investigate the members, or even seek samples of relatives’ DNA to narrow the suspect pool. “How can we ignore that?” asks Lt. Kevin Lawson, who supervises the St. Louis County police crime lab. The technique could put heat on cold cases, increasing the number of hits by 40 percent. Last month, California became the first state to embrace the familial DNA search as a crime-fighting tool. Massachusetts could be next. Maryland is the only state to ban it. St. Louis County Prosecuting Attorney Robert McCulloch called familial DNA searching “a great idea.” He said: “Any sort of an investigation does the same thing,” he said. “If you have a murder, the first person you go to are family members.”