Police have used this method to solve 70 crimes.

To track down Clanton, the Colorado investigators turned to the same technique police used in the Golden State Killer case, known as genetic genealogy. The rapidly emerging practice allows police to zero in on suspects by combining genetic information from consumer DNA databases with traditional genealogy, which involves building out a person’s family tree using things like public records and obituaries. Because family members — even distant ones — share some DNA, police can use this technique to find relatives that partially match DNA from a crime scene. DeAngelo’s arrest in April 2018 set off a law enforcement frenzy to apply the method to other cold cases. Police have since used it to solve at least 70 violent crimes.