Because investigators had DNA samples taken from the Golden State Killer's crimes, they used that to their advantage. According to the New York Times, investigators set up a fake profile on the genealogy website GEDmatch and submitted the Golden State Killer's DNA. Their search turned up several distant relatives as well as some character traits for which to be on the lookout. A second New York Times article reported that the GEDmatch site had an eye color and hair predictor tool that led investigators to believe that their suspect had blue eyes and was balding. Using that and the distant relatives from the genealogy site, investigators were able to narrow down the Golden State Killer's family tree to the man they suspected: Joseph James DeAngelo. From there, officials gathered his DNA from DeAngelo's car door handle and a used tissue that he'd thrown away. His arrest followed shortly after in April 2018.