BAD FORENSIC SCIENCE: DNA search for California serial killer led to wrong man.

Investigators hunting for the so-called Golden State Killer turned to searching genetic websites in 2017 but misidentified an Oregon man as a potential suspect. A year later, after using a similar technique, they are confident they’ve caught the serial rapist and killer who eluded capture for four decades.

In March 2017, an Oregon City police officer, working at the request of investigators in California, convinced a judge to order a 73-year-old man in a nursing home to provide a DNA sample.

Court documents obtained by The Associated Press said detectives used a genetic profile based off DNA from crime scenes linked to the serial killer and compared it to information on a free online genealogical site.

Investigators cited a rare genetic marker, which the Oregon man shared with the killer, to get the judge to issue the order. The Oregon City man is in extremely poor health in a rehabilitation facility and was unable to answer questions Friday.

His daughter said his family was not aware that authorities took a DNA sample from him while he was lying in bed at the rehabilitation center until she was contacted by the FBI in April 2017 and asked to help expand the family’s genetic tree in the search for suspects.

The woman, an amateur genealogist, cooperated, but ultimately investigators determined none of her relatives were viable suspects, she said. The woman spoke to The Associated Press on condition of anonymity because she did not want the family’s name publicly linked to the case.

No harm done, I guess, but not entirely confidence-building.