What may yet prove to be the biggest murder spree in Los Angeles history languished unsolved for three decades, a question mark haunting the files of the LAPD cold-case unit.
The horrors of the so-called "Westside Rapist" were a daily staple of local papers in the 1970s, leaving law enforcement feeling helpless and striking terror in the community, especially those most vulnerable members who fit the profile of the killer's victim of choice.
The unidentified stalker sowed fear with a sickening chain -- dozens -- of rapes and murders of elderly women in their homes.
"He was a pretty vicious guy, frightened a lot of people and killed a lot of people," said George Beck, the now-retired LAPD deputy chief in charge of the case at the time. "He attacked older women living alone. And sometimes women in outside situations, in a parking lot or alley. ... We couldn't catch up with him.
"There was a lot of anxiety on the part of older women."
Now, thanks to cutting-edge lab technology and a dose of luck, Detectives Rick Jackson and Richard Bengtson say they've done what their predecessors couldn't; they finally cracked the case.
The break came in the course of a hunt for another killer, a perpetrator from the 1980s known as the "Grim Sleeper." Lab analysts such as Nick Sanchez were reviewing DNA samples on previous offenders one by one, hoping for a match.
"I had one coroner a vaginal slide to work with," Sanchez said, describing the meager thread of evidence in the Westside Rapist case. "And that was created back in 1972."
The search turned up no matches for the Grim Sleeper. But the 1972 slide did produce one hit.
"I mentioned something about, 'Oh yeah, I just got a 1972 CODIS hit' -- and Detective Bengtson said, 'I think that's my case!'" (CODIS, the Combined DNA Index System, is a DNA database.)
The Westside Rapist, police allege, is a 72-year-old insurance adjuster named John Thomas Jr., who's in police custody on two murder charges. He is scheduled to enter a plea in a court appearance later this month.
"We strongly believe that Mr. Thomas is the Westside Rapist," LAPD Deputy Chief Charlie Beck said at a news conference earlier this month.
Police would have the chance to interview Thomas. Meanwhile they drew links from murder to unsolved murder, framing the work of an alleged serial killer of unprecedented proportions.
"The numbers could be astronomical," Bengtson said. "If we are able to put together the cases that we think that he's involved in, it could be in the 20s to 30s for murders. ... If we are able to link him to the cases we think he was involved in, that would make him L.A.'s most prolific killer."
They found the alleged perpetrator almost by accident, while taking samples from old registered sex offenders.
It was the case of Ethel Sokoloff, raped and murdered at age 68 in 1972, that provided the alleged DNA link to Thomas, as well as an unsolved murder case from 1976.
"This wasn't a first-time offender," said Bengtson's partner, Jackson. "You can tell from the complexity of the crime. ... Complex in the sense that you are taking the liberty of going in a house, most likely knowing somebody is in there, probably knowing that it's an elderly female already, that lives by herself. Because what we saw after this case was a pattern of elderly females that all lived alone being attacked."