He passed a polygraph about a sadistic killing... then DNA tied him to the crime

A California man who passed a polygraph test denying his involvement in a sadistic killing almost 50 years ago has been identified as the suspected murderer.

Esther Gonzalez, 17, was raped and bludgeoned to death while walking from her parent's house in Beaumont to her sister's house in Banning on February 9, 1979, the Riverside County District Attorney's Office said.

Her body was found "dumped in a snowpack" alongside Highway 243 in Banning the next day, after an unidentified man called the Sheriff's Department to report that he had found a body.

Deputies said he was 'argumentative' and declined to say whether the victim was a man or a woman.

After five days of investigating, police identified the caller as Randolph 'Randy' Williamson, whom they asked to undergo a polygraph test.

'He agreed and passed which, at the time, cleared him of any wrongdoing,' the District Attorney's Office said.

Williamson, a US Marine Corps vet, then spent the next 35 years living a normal life, eventually moving to Florida, where he died in 2014.

But California detectives continued to work on the cold case, and determined earlier this year that 'although Williamson was seemingly cleared by the polygraph in 1979, he was never cleared through DNA because the technology had not yet been developed.'

The break came last year, when cold case homicide detectives sent various items of evidence to Othram, Inc. in Texas to conduct a forensic genealogy, which they hoped could lead them to the killer.

Among the DNA samples sent to the lab was a blood sample collected during Williamson's autopsy following his death in 2014.   

That was proven to be a match to the semen sample collected from Gonzalez's body, which had earlier been uploaded to the Combined DNA Index System, which catalogues DNA samples.

It is unclear whether Williamson knew Gonzalez or had a motive for killing her.

Police said they found some old assault allegations against Williamson, but he did not have any convictions for violent crimes and his DNA never matched with any of her rapes or murders, the Los Angeles Times reports.

Officials with the District Attorney's Office are now seeking any information on Williamson, Gonzalez and 'other potential victims.'

But they say they are glad to have found an answer for Gonzalez's family after all these years.

'This killing still haunts them,' Jason Corey, an investigator with the DA's Office, told the LA Times. 'But Esther was never forgotten by us all these years.;