Robert Durst, the real estate heir recently convicted of killing his close friend and suspected of killing two others, including his wife, is asking for a new trial, alleging he was prevented from receiving a fair shake during the lengthy proceedings. 

Lawyers for the 78-year-old filed papers Thursday asking a California court to order a new trial after Durst was found guilty of killing Susan Berman by a Los Angeles County jury last week. 

Prosecutors alleged Durst killed Berman in 2000 before she could talk with authorities about how she provided a false alibi for him when his wife, Kathie McCormack Durst, vanished in 1982. During the trial, they accused him of killing his wife and then getting rid of Berman years later to cover up the first slaying. Kathie Durst has never been found and has been declared legally dead.

ROBERT DURST MURDER TRIAL LAWYER SAYS PROSECUTORS DEMONIZED 'SICK, OLD MAN'

New York real estate scion Robert Durst, 78, answers questions from defense attorney Dick DeGuerin, left, while testifying in his murder trial at the Inglewood Courthouse on Aug. in Inglewood, Calif. Defense attorneys on Thursday requested a new trial for Durst, alleging several missteps prevented him from receiving a fair proceeding. (Gary Coronado / Los Angeles Times via AP, Pool)

In their filing, defense lawyers said there was insufficient evidence to convict their client. 

"Specifically, there was insufficient evidence to establish that Mr. Durst committed First Degree Murder and that he shot and killed Susan Berman with a firearm," the filing states, which was obtained by Law & Crime Network. "Moreover, there was insufficient evidence to establish the special circumstance that Mr. Durst killed Susan Berman because she was a ‘witness.'"

They noted that the lead investigator in the disappearance of Kathie Durst "found no evidence to support that Mr. Durst killed Kathie Durst or that Susan Berman was a witness or assisted Mr. Durst in any criminal law."

They also reiterated that no murder weapon was ever recovered and that there was no forensic evidence to prove Durst killed his wife or Berman. 

"Here, rather than relying on forensic evidence at trial, the prosecution largely relied on witnesses who provided statements to law enforcement, many years after Susan Berman's death," court documents said. 

Prosecutors share photo of Robert Durst (left), Susan Berman (middle) and Kathie Durst (right) at Robert Durst's Aug. 11 murder trial.  (Fox News)

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They also presented a list of reasons they believe Durst was prevented from receiving a fair trial, including the lengthy delay of the proceedings, which were interrupted by the COVID-19 pandemic, and evidence of possible Kathie Durst sightings in New York City not being allowed to be presented to jurors. 

Prosecutors also argued that the court erred by allowing jurors to see the "The Jinx," an HBO documentary about Durst. 

Durst has said he regretted participating in the 2015 miniseries. In the final episode, he was famously caught on a hot mic saying, "What the hell did I do? Killed them all, of course."

A sentencing hearing for Durst is scheduled for Oct. 18.