Long haul:

Cold case investigator who spent 22 years chasing the East Area Rapist retired just before the arrest of a suspect.

The day before his retirement, Paul Holes parked a white Ford Taurus outside the Citrus Heights home of James Joseph DeAngelo.

At that time, neither he nor DeAngelo knew the latter would be arrested at the same house a month later, his DNA and other evidence allegedly connecting him to 12 slayings and 45 rapes in California from 1976 to 1986.

It was the end of March, and Holes — a longtime coldcase investigator for the Contra Costa County district attorney’s office — was a central member of a multiagency team that had narrowed down the list of suspects in the case of the East Area Rapist, also known as the Golden State Killer, to a handful of men.

The team had taken a novel approach, running crimescene DNA against consumer genealogical websites in a bid to find the killer or his relatives. Holes had been involved in the case for 24 years, and this was the closest investigators had ever been. Or maybe not.

DeAngelo was the only man in the small group of suspects Holes visited.

The day before he turned in his department firearm, something brought him to the modest one-story home of the 72-year-old ex-cop and grandfather. DeAngelo’s age and other traits seemed to fit, and his past locations appeared to correlate with the series of rapes and homicides across California, Holes said.

“At that point, literally, I was just curious,” Holes said by phone Thursday, a day after authorities announced DeAngelo had been arrested and was being charged with murder in multiple counties. “Where is this guy living? At that point, he was just one of several. He’s just a maybe.”

Holes wrestled with whether to knock on the door and ask DeAngelo, “Can I get your DNA?”

But he didn’t. He drove away and retired the next day.

Now, Holes said, he’s glad he sat in his car. There’s no telling what would have happened, and it turned out that knocking on the door wouldn’t be necessary.

Sacramento County sheriff ’s deputies began surveilling the home last week and were able to obtain two “surreptitious samples” from DeAngelo, meaning they waited for him to discard something — perhaps a cup or bottle — with his DNA on it, officials said.

The first sample was too weak, Holes said, so investigators got another and tested it, finding a match to the killer’s

“At that point, literally, I was just curious. ... He was just one of several.”

Paul Holes, investigator

DNA.

It was an exhilarating peak for Holes in a chase that began in the 1990s, when he worked on the case in the early years of DNA evidence.

“It’s been very frustrating. You have your moments of highs thinking you got the guy, and then you crash when the DNA evidence eliminates him,” Holes said. “The frustration just builds. To finally get to the point where you find the right guy, it is a very good feeling.”

The cold case was not only Holes’ most difficult — it was his first. He began looking for the East Area Rapist in 1996.

A year later, DNA evidence definitively linked three Contra Costa County rapes — two in Danville and one in San Ramon — to a serial killer and rapist who had started out in Sacramento County, though detectives had already made the connection based on the suspect’s methods, Holes said.

He then sought to connect the crime spree in Northern California to similar attacks in Southern California. The use of DNA in forensics was in its infancy, and it took four years before investigators verified in 2001 that the rapes and killings were committed by the same person, Holes said.

In 2016, law enforcement officers from around the state formed a task force to hunt for the East Area Rapist.

Holes’ colleagues are now marveling that his dogged work finally paid off. But he declined to describe the critical break in the case — how investigators used the genealogical websites to find DeAngelo.

“Those types of details I’m not at liberty to comment on,” he said. “We were leveraging anything we could.”