PLACERVILLE, Calif. (KTXL) -- Answers are surfacing four decades after two brutal killings in South Lake Tahoe.
Carol Andersen was only 16 when she was found dead. The Zephyr Cove high school student was last seen leaving a party.
Brynn Rainey worked at a casino. Investigators say in the summer of 1977 the 27-year-old's body was found in a shallow grave.
The El Dorado County Cold Case Task Force identified suspect Joseph Holt with the help of genetic genealogy.
Ballard said these difficult cold cases are getting solved because of the growth and popularity of public DNA databases, like GEDmatch, which law enforcement agencies can access without court orders.
In El Dorado County, investigators had preserved DNA from a blood stain and one of the victims' bodies.
Using the database, a family tree and more testing, Holt was identified.
"Joseph Holt was never on the radar," John Gaines, an investigator with the El Dorado County District Attorney's Office, explained.
Investigators say Holt was from San Jose. A graduate of the University of California, Berkeley, he worked in real estate in South Lake Tahoe before dying of heart attack in 2014.
El Dorado County investigators believe Holt is responsible for more crimes. Their task force asks anyone with information to call their tip line, (530) 621-4590.