By Da Lin

CITRUS HEIGHTS (KPIX 5) – The district attorney’s office said investigators tracked down the golden state killer suspect by using genealogy websites.

Apparently, the DNA closely matched DNA samples collected from old crime scenes.

READ MORE: Asian American Attacks: San Francisco Shop Owner Says Teen Thief Pepper Sprayed Her

And once investigators had a starting point, they say all the clues led them to Joseph DeAngelo.

Investigators spent the last two days going through every part of DeAngelo’s house. They want to learn as much about him to build their case.

Just 15 minutes away, the arrest is the big talker among his former co-workers at a large Save Mart distribution center.

Robert Schoentges worked with Deangelo for 12 years.

“When I saw the picture of him I said: that’s Joe. I said: no way. And then it became confirmed, and I said: Good God,” Schoentges said.

A company spokeswoman says DeAngelo worked as a mechanic there for 27 years and retired last year.

READ MORE: Santa Clara Wins NCAA Women's Soccer Championship, Topping FSU In Penalty Kick Shootout

“I’m a driver and he does the repairs,” Schoentges said.

Schoentges said he thought DeAngelo was just an average Joe who apparently loves to fish.

“He was a normal working person. He did his job, he did it well…It’s just hard to believe because he was, he was really reserved. He was really quiet and was really secretive. You know, he didn’t say much. Little bit of temper, but not much,” Schoentges said.

The company says DeAngelo started working there in 1990.

“It’s a sad thing and I’m sorry for the people that he did what he did,” Schoentges said.

Detectives say the the golden state killer, also known as the east area rapist, murdered at least 12 people and raped more than 50 women from 1974 to 1986.

“How could you live a normal life, knowing what you’ve done and just go to work everyday like nothing ever happened?” Schoentges said.

MORE NEWS: UPDATE: 2-Alarm House Fire Contained In San Francisco's Bayview District

We don’t know which genealogy websites investigators used. We do know that DeAngelo has at least two adult children and that he is divorced. He will be in court on Friday.