It was a case that captivated the public four decades ago because of its shocking circumstances and a celebrity connection: Who killed Karen Klaas?
On the morning of January 30, 1976, shortly after dropping her young son off at school, Klaas returned to her home in Hermosa Beach, California.
There, the 32-year-old mother of two was sexually assaulted and strangled with her own pantyhose.
By the time police discovered her, Klaas was unconscious. She was taken to a hospital, where she remained comatose for five days, then died on February 4, 1976.
For nearly 41 years, the case would remain Hermosa Beach's longest-running cold case. The brutal killing shook the small oceanfront California city that, even now, sees only a handful of murders per decade.
Klaas also was the ex-wife of singer Bill Medley of the musical duo Righteous Brothers, which rose to fame in the 1960s with hits like You've Lost That Lovin' Feelin' and Unchained Melody.
At the weekend, nearly 41 years to the day after the crime was committed, the Los Angeles County Sheriff's Department announced it had finally been solved.
"I just kind of became numb," Medley said at a news conference today, describing the recent phone call notifying him that his former wife's killer had been identified through an emerging DNA-testing technique.
As he spoke, Medley was surrounded by Klaas' two sons and investigators who had worked on the case, some since day one.
"This is something you've been hoping for or speculating about for 40 years," Medley said. "All of a sudden, they say, 'We got it.' "
Officials said they identified Klaas' killer as Kenneth Troyer, a man born in 1946 who later was identified in several sexual assaults in southern California.
In early 1982, Troyer escaped from prison in San Luis Obispo; in March of that year, he was shot and killed by police in Orange County, said Los Angeles County Sheriff Jim McDonnell.
At the time of Troyer's death, there were no laws requiring his DNA be entered into a database for convicted rapists, McDonnell said. For that reason, even though detectives had been able to obtain a DNA profile of Klaas' murderer in the 1990s, there was never an exact match when they processed it.
In 1999, detectives released new details about Klaas' suspected killer - a "shaggy-haired, bearded man in a trench coat and blue jeans" - based on two witnesses who said they had seen him leaving Klaas' house, AP reported then. That same year, they used DNA processing to eliminate five original suspects. Still, Klaas' case languished.
At the time of her death, Klaas had been divorced from Medley for about four years and remarried. Officials ruled out her new husband as a suspect, according to CBS Los Angeles.
In 2011, a "familial DNA" search was conducted for the first time.
The technique had emerged in recent years as a way for investigators to search for "close-to-perfect matches" among relatives of a convict, the Washington Post reported in 2008.
However, the technique also attracted criticism and ethical questions from those who argue that family members could become "genetic informants" without consent.
"If practiced routinely, we would be subjecting hundreds of thousands of innocent people who happen to be relatives of individuals in the FBI database to lifelong genetic surveillance," Tania Simoncelli, science adviser to the American Civil Liberties Union, told the Post at the time.
The search turned up nothing. But unknown to them at the time, a man related to Troyer had committed a "qualifying crime" that would soon result in his own DNA being collected and uploaded into the federal database.
Last year, investigators ran one more familial DNA search. This time, they came up with a match. Based on additional evidence, detectives say they determined Troyer was the man who had killed Klaas in 1976.
Though they were unsure of an exact motive, investigators found Troyer had a relative who lived near Klaas, which would have explained why he was in the area, McDonnell said.
Darrin Medley, Klaas' older son, said he was grateful to the investigators for allowing them to "experience the joy of closure".
"I couldn't be more blown away with the technology," Darrin Medley said. "I want to give hope to other families that this kind of technology can be utilised to identify criminals. It's extremely important."
Bill Medley said he had been grappling with the unsolved case over the last 40 years, and at some point "came to terms" with the thought that it would never be solved.
We miss Karen and the most important thing is the boys didn't get to grow up with their mother
"There's been a voice in the back of my head, probably Karen, telling me since about 20 years ago, 'Drop it. Let it go. This guy is either dead or he's in prison,'" he said. "It's just nice to close the book on this."
Bill Medley added that Klaas remained one of his best friends even after their divorce, about four years before her death.
"We miss Karen and the most important thing is the boys didn't get to grow up with their mother," he said. "She would have been an incredible grandma [as well]. She was a wonderful, wonderful girl."
Los Angeles County District Attorney Jackie Lacey told reporters Monday that familial DNA was used only as "a last resort" for serious cases in which all investigative leads were exhausted.
The Klaas case was only the second in the county in which investigators had identified a suspect using familial DNA, she said. The first was in 2010, when the technique was used to identify Lonnie David Franklin as the "Grim Sleeper" serial killer.