In year after arrest of alleged Golden State Killer, many cold cases closed

OAKLAND, Calif. (KTVU) -  Alleged Golden State killer Joseph DeAngelo was arrested in April 2018, thanks to genetic genealogy identifying a suspect using DNA, public websites and family trees.

"A year ago today, I was driving back from LA and my phone started ringing," said retired Alameda County prosecutor and DNA expert Rock Harmon.

Harmon says DeAngelo's arrest marked the start of a new era in crime-fighting.

"Golden State Killer happened and boom! You know?" Harmon said. "Nobody had any idea that this was really going to happen, that it could be as good as it is."

But it's happened. And investigators say it's as good as it can get. 

Public genealogy websites used to find missing people and the birth parents of adoptees are now being transformed into a law-enforcement tool.

Accused NorCal Rapist Roy Waller, a UC Berkeley employee, was busted 27 years after his alleged spree began.

Russell Guerrero was arrested 28 years after Jack Upton was found beaten, stabbed and strangled in his Fremont apartment.

John Arthur Getreu was nabbed 45 years after the body of Leslie Perlov was found in the hills above Stanford University. 

Parabon Nanolabs is among the companies working with law enforcement. Over the past year, it's helped solve more than 50 cases across the country, many of them in California.

After DeAngelo's arrest, ancestry websites like GEDmatch made it clear: you can opt out if you have concerns law enforcement is checking out your DNA profile. 

"The Golden State Killer arrest really opened the door for me to feel that I could ethically pursue this work," said CeCe Moore, chief genetic genealogist for Parabon Nanolabs. "I think California's embraced this new technology and the promise of this more so than any other state."