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LOS ANGELES — More than four decades after the ex-wife of Righteous Brothers singer Bill Medley was raped and killed, officials announced Monday they used DNA to identify a suspect in the slaying: a man who was killed by police in 1982.

Los Angeles County Sheriff Jim McDonnell said investigators believe Kenneth Eugene Troyer was responsible for the January 1976 slaying of Karen Klaas.

The 32-year-old was attacked Jan. 30, 1976 as she returned to her home in the Hermosa Beach neighborhood, was sexually assaulted and strangled with her pantyhose. She never regained consciousness and died a few days later at the hospital.

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Singer Bill Medley of "The Righteous Brothers" attends an event with his wife Karen Klaas, circa 1969, in Los Angeles. Michael Ochs Archives / Getty Images

Investigators used a controversial DNA testing technique, known as familial DNA, to compare a sample of DNA that was collected at the crime scene and were able to identify a "first-degree relative" of Troyer, Sheriff's Capt. Steve Katz said.

Officials would not identify the relative and would only say the sample they used was in a state database of convicted felons.

The technique, which has raised ethical issues in the forensics community, allows investigators to search law enforcement databases to identify likely relatives of the person who may have committed the crime. Law enforcement officials have argued the technique can provide investigators with valuable leadsmba.

"Because of the familial DNA search, detectives were able to link Troyer's DNA and positively confirm his identity as the killer," McDonnell said Monday as he stood alongside Medley and more than a dozen other law enforcement officials. "Familial DNA search is the only reason Troyer was identified in this horrific crime."

Troyer, who had been suspected of committing several other sexual assaults in California, was shot and killed by police after escaping from a California prison in 1982, McDonnell said. As investigators began to hone in on him as a possible suspect last year, they were able to obtain a sample of his DNA that was held in the Orange County coroner's office and conclusively link him to Klaas' slaying, Katz said.

The arrest brought closure to a family that has struggled with questions for decades, Medley told reporters at a news conference Monday.

"It's been something we've been hoping for and speculating about for 40 years and all of a sudden they say, 'We got him and here's who did it,'" Medley said. "It's just nice to be able to close the book on this."