"I can still remember it. I couldn't tell if it was a screaming baby or a cat being killed. It was a horrendous, horrendous scream. It was terrifying," remembers actor Jon Gries, who was 19 then, and was staying at his mother's house just down the street from where Christa was attacked.
Gries ran into his yard but didn't hear anything more, or see anything, and went back inside. "The next day the sheriff came knocking on the door. They asked if any of use had heard anything unusual in the night," he remembers. "And they told me someone had been murdered. I remember the police officer saying, had I walked into the street I would have seen her, but I only looked down the sidewalk."
It turns out Gries had a connection with Christa. "There were a lot of girls like Christa-I met her a couple of times-beautiful girls who just kind of seemed to work their way through the various corners of Hollywood."
As the detectives started to investigate, they soon realized that the case would be very difficult. With Christa's complicated life, there were plenty of people who might want to kill her.
At first, detectives thought Christa's murder might be connected to another sensational killing, the stabbing of actor Sal Mineo, best known for co-starring with James Dean in "Rebel Without A Cause."
The papers had a field day with the similarities: Christa had been stabbed and bludgeoned to death in front of her agent's house in West Hollywood; Mineo was murdered one year earlier on the very same day, Feb. 12, in the very same neighborhood. There were no known witnesses in either case.
But the Mineo lead fizzled. The suspect in his murder was believed to be in jail when Christa was killed. So detectives started to look more closely at Christa's celebrity-studded love life and her infamous diary. Was it research perhaps for a tell-all book?
But Christa's scandalous diary had vanished. It may have been in her purse, which was missing from the crime scene. With that crucial piece of evidence gone, investigators hit a string of dead ends.
Nicole mourned the loss of her mother and the life they were supposed to have together. She raised her own family in the Northeast, but a few years ago felt compelled to find out what really happened.
After years of pressure from Nicole, a new generation of homicide detectives, Larry Brandenburg and Tom Harris of the L.A. County Sheriff's Department cold case unit, took the case.
Christa's written diary wasn't the only way she kept track of that long list of lovers: it turns out Christa was tape recording her sexcapades with all those celebrity boyfriends.
The investigators say the tapes are a "very significant" part of this case, because those tapes could have supplied a motive for someone to kill Christa. "We don't know if there may have been extortion or a thought of extortion," Det. Harris says.
Christa's friend Darlene warned her against making the tapes. "I thought it was dangerous," she says. "I thought she was playing with fire."
But just like Christa's diary, most of those tapes have disappeared too. The hunt for the missing tapes has led detectives to another new twist, an angle right out of "The Sopranos."