Transcript for DNA Evidence May Solve 40-Year-Old Murder Mystery
And next tonight, a murder mystery spanning more than 40 years. Tonight, possibly solved. The ex-wife of bill medley, the victim of a brutal death in 1976. Police say DNA evidence has finally led them to a suspect. Here's Marci Gonzalez. Reporter: Investigators revealing the controversial technique that led them to the person that they say sexually assaulted and killed the ex-wife of righteous brothers singer, bill medley. The Los Angeles sheriff's department said they tracked down the killer using familial DNA searching. When a partial match is used to find likely relatives in a suspect. It's been used to solve seven other cases in California, including that of the so-called grim sleeper. Crime scene DNA leading to the serial killer's arrest 25 years after his murder spree began. And in New York, investigators pushing to use it in the killing of a jogger, but others saying it's led to false leads and they call it an invasion of privacy. Family members are now subject to questioning. That certainly is not fair. Reporter: The L.A. Sheriff's department has not released any details on the suspect. They say they'll do it tomorrow, 41 years to the day after the attack. Marci, thank you. And there's still much more
This transcript has been automatically generated and may not be 100% accurate.