After 45 years, authorities in California were finally able to tell the Gonzalez family who they believe killed their loved one. The Riverside County Sheriff’s Office used DNA and forensic genealogy to identify the suspected killer, who turned out to be the same man who reported finding Esther Gonzalez’s body to authorities.

On February 9, 1979, 17-year-old Gonzalez was walking to her sister’s house in Banning, California, about 85 miles east of Los Angeles. She never made it home.

The next day, her body was found in a snowpack off a highway near Banning, the Riverside County District Attorney’s Office said in a news release. She was attacked during her walk, raped and bludgeoned to death, authorities said.

Deputies described the unidentified man who found the body as “argumentative,” according to the news release. The man, later identified as Lewis Randolph “Randy” Williamson, called the county sheriff to report the body and said he didn’t know whether it was a man or woman. Williamson was later asked by sheriff’s investigators to take a polygraph test.

The district attorney’s office said he agreed to the test and passed, which “at the time, cleared him of any wrongdoing,” according to the release.

Nearly five decades later, the district attorney’s office said a cold case homicide team used forensic genealogy to confirm Williamson is Gonzalez’s suspected killer.

Forensic genealogy is surging across the country as investigators analyze DNA in addition to traditional genealogy research to generate leads for unsolved cases.

Jason Corey, the master investigator for the Riverside County Sheriff’s Office, said the technique is a tremendous addition to an investigator’s toolbox.

“I think it will be a great investigative tool moving forward in the future,” Corey said. “It will help do a lot of good and not only identify victims, but it will help point the investigators in a direction with their investigative leads that will help bring those suspects to justice.”

Even as the Gonzalez case went cold, Riverside County detectives kept searching.

The homicide team continued to investigate the case for decades after Gonzalez’s death. The team uploaded a semen sample from the crime scene into the Combined DNA Index System but there weren’t any leads.

In 2023, detectives sent various items of evidence to a genetic lab in Texas that specializes in forensic genealogy and identifying victims in unsolved murders.

Earlier this year, a crime analyst laid out all the facts of the case.

Then, the light bulb went off.

“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 district attorney’s office said.

Conducting another polygraph was not an option, as Williamson died in Florida in 2014.

However, a blood sample had been collected during his autopsy.

Authorities in Florida sent the sample to the California Department of Justice, which confirmed Williamson’s DNA matched the DNA semen sample recovered from Gonzalez’s body.

Corey said this case was in Riverside County’s cold case unit since it launched about five years ago. Over the years, multiple investigators have worked on the case. That all came to an end this Wednesday.

“I can’t imagine what it’s like for them,” Corey said. “That whole family has just been devastated over the years. This is a day in and day in, day out thing. I don’t think this is something that ever got easier for them as time went on.”

“I don’t know if you can say you’re happy that it’s done, because it’s still, it’s still a terrible tragedy, but I hope it can bring them some closure,” Corey said.

The latest development in the cold case does bring peace and closure to the Gonzalez family, Esther’s older sister Elizabeth said. She was happy to hear her sister’s suspected killer was finally identified.

“We are very happy that we finally have closure,” Elizabeth Gonzalez, 64, wrote in an email to CNN. “We are happy about it but, since the guy has died, a little sad that he won’t spend any time for her murder.”

Esther and Elizabeth Gonzalez grew up very close as they were only one year apart in age. Esther is now remembered by her family for her shy yet funny and mild-mannered personality. She the fourth out of seven children.

Esther’s oldest brother, Eddie, wrote on Facebook, “The Gonzalez family would like to thank the Riverside County sheriff’s department on a job well done after 40 years the Gonzalez family has closure.”