New genetic sleuthing tools helped track down the Golden State Killer suspect

Using DNA to find a killer sounds easy: Upload some DNA to a database, get a match and — bingo — suspect found. But it took new genetic sleuthing tools to track down the man suspected of being the Golden State Killer.

Investigators have confirmed they used a public genealogy database, GEDmatch, to connect crime scene evidence to distant relatives of Joseph James DeAngelo. The 72-year-old former police officer, arrested April 24 at his home in Sacramento, is suspected in a string of about 50 rapes and 12 murders committed between 1974 and May 1986.

The news prompted a flurry of concerns about privacy and ethics — there’s no telling how many people in the public database are being subjected to what amounts to a “genetic stop and frisk,” says Alondra Nelson, a sociologist at Columbia University. But others say they doubt police are actively trolling genealogy websites for suspects. Too many resources are required to do this sort of work, says Sara Katsanis, a genetics policy scholar at Duke University’s Initiative for Science & Society. “I don’t think this...