Real estate heir Robert Durst, 76, has pleaded not guilty to murder in the 2000 killing of Ms Berman in her Beverly Hills home.
Susan Berman sealed her fate when she told best friend Robert Durst, falsely, that detectives had asked to talk to her about Durst's wife's disappearance 18 years earlier, prosecutors said on Thursday.
Durst allegedly told Ms Berman that she should agree to be interviewed, but privately made his own plan.
"Though he told her, 'Go talk to them,' he also decided to kill her," Los Angeles Deputy District Attorney John Lewin told jurors during a second day of opening statements in the trial of the wealthy New York real estate heir.
Durst, 76, has pleaded not guilty to murder in the 2000 killing of Ms Berman in her Beverly Hills home.
Mr Lewin outlined the last days of Ms Berman's life, when Durst was scrambling around the country, stockpiling money and setting up the false identity of an elderly mute woman because authorities had reopened the investigation into the 1982 disappearance of his wife.
Durst has never been charged in connection with the disappearance of wife Kathie Durst, who was later declared dead, but prosecutors in the Berman murder trial have been allowed to present evidence that Durst killed her, told Ms Berman, who acted as his spokeswoman and helped him cover his tracks, then shot Ms Berman in fear of what she might tell investigators.
Mr Lewin said that while New York detectives did in fact intend to talk to Ms Berman, and had already spoken to her friends, they hadn't actually approached her yet, and did not say why she might have told Durst they had, but it was a fatal error because Durst believed it and acted on it.
"She said 'Bobby it would be best for both of us if I just talked to them,'" Durst said while recalling the phone conversation in an interview for the HBO documentary series, "The Jinx." That 2015 program helped lead to his arrest in Ms Berman's killing.
"What am I going to say, 'no?'"
Durst was already on the run at the time of the conversation. After learning through his family company that police were investigating his wife's death again, he began stockpiling cash, stopped using his cell phone, married a woman he had dated previously and signed over power of attorney to her in what he called a "marriage of convenience." He rented a small apartment in Galveston, Texas where he would live and pose as a mute elderly woman named Dorothy Ciner, a name taken from a high school classmate.
"I decided I had to go into hiding," Durst said in another "Jinx" clip played for jurors. "People are going to find me guilty. I've been guilty for years in the newspapers, now they're really going to find me guilty."
Authorities have never been able to place Durst in the Los Angeles area at the time of Ms Berman's killing, though they have long known he was in California, and Mr Lewin laid out for jurors the pile of circumstantial evidence on Durst's whereabouts.
Durst had taken a bus from Texas to New York, and four days before Ms Berman's killing he flew on a small private shuttle to the Eureka area in Northern California, where he kept an office and an SUV that he took out of storage, Mr Lewin told jurors.
The next day, December 20, 2000, he used a calling card to check his voicemail messages off a highway 112.65 kilometres to the south of Eureka. His whereabouts were unknown until he bought a late-night plane ticket in San Francisco on December 23, the night after Mr Berman was killed.
The mileage on Durst's SUV, which he did not have much access to afterwards, was consistent with his having driven to Los Angeles and back to San Francisco, Mr Lewin said.
Mr Lewin then told jurors of evidence familiar to viewers of "The Jinx," a letter sent to police that had Ms Berman's address and the word "CADAVER" on it. Durst's attorneys conceded in the run-up to trial that Durst had written it but have yet to explain it, and prosecutors played a clip of a Durst interview in which he says only the killer could have written it.
Nine months later while hiding in Galveston, Durst was arrested and charged with the murder of his elderly neighbour Morris Black. At his trial in 2003, Durst told jurors Mr Black had been in his apartment with a gun that went off accidentally during a struggle that killed Mr Black.
Durst testified that he dismembered the body and threw it in the Gulf of Mexico, but was acquitted.
Los Angeles prosecutors are being allowed to use evidence of Mr Black's killing in the Berman case, and Mr Lewin on Thursday made it clear he essentially intends to show Durst was guilty of murder in that case.
Lewin gave a detailed account of the dismemberment and repeatedly told jurors that Durst "murdered" Mr Black, prompting one of several clashes with Durst's lawyer Dick DeGuerin, who was also his attorney at the Texas trial.
"Mr Lewin keeps saying 'murder,' he was found innocent of murder," Mr DeGuerin said.
"He was found not guilty," Mr Lewin snapped in response.
"There's not much difference," Mr DeGuerin said.
"Oh yes there is!" Mr Lewin shouted.
The judge overruled Mr DeGuerin's objection and repeatedly urged the lawyers to calm down.
Source: 9News https://www.9news.com.au/world/robert-durst-victim-susan-berman-real-estate-heir-murder-trial/fd9df299-4318-406d-9ddc-f254a39ef75e