LOS ANGELES (AP) — New York real estate heir Robert Durst was sentenced Thursday to life in prison without the possibility of parole for the killing of a longtime friend in her Benedict Canyon home just over two decades ago.

Durst, 78, sitting in a wheelchair, was quiet as Los Angeles County Superior Court Judge Mark E. Windham pronounced the sentence. His attorneys have vowed to appeal his conviction for the killing of Susan Berman, who was shot in the back of the head just before Christmas Eve 2000.

Durst was convicted Sept. 17 of first-degree murder, with jurors also finding true the special circumstance allegations of murder while lying in wait and murder of a witness. Jurors also found true allegations that Durst personally used and discharged a firearm during the commission of the crime.

Prosecutors argued that Durst shot Berman and then his neighbor, Morris Black, in Galveston, Texas, nine months later in the head because each of them had damaging information against him and feared they would speak to authorities after a re-investigation was launched into the 1982 disappearance of his first wife, Kathleen "Kathie" Durst, whose body has never been found.

Durst spent 14 days on the stand and repeatedly denied being involved in Berman's killing, and testified that he wrote a so-called "cadaver" letter to police after finding Berman's body while using a key she had sent him to enter her house.

Durst has denied any involvement in his first wife's disappearance, and he was acquitted in Texas of Black's murder after testifying that the gun went off during a struggle over the weapon.

Durst's trial began in March 2020, initially at the Airport Courthouse in Los Angeles. The trial was subsequently moved to a larger courtroom in Inglewood due to social distancing concerns because of the COVID-19 pandemic, which quickly forced a delay of about 14 months in the trial. Jurors returned to court in mid-May, when attorneys gave a new and abbreviated round of opening statements before testimony resumed.

Within less than a week of the jury's verdict, Durst's defense team filed a motion seeking a new trial for their client. The defense contends that there was "insufficient evidence to support the conviction beyond a reasonable doubt, and the verdict was contrary to the evidence and the law."

"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," the defense team wrote in the filing. "Additionally, it is respectfully submitted that the testimony of Mr. Durst did not establish that he shot and killed Susan Berman."

The defense added that the evidence at trial "only established his mere presence at the scene after he located Ms. Berman's body" and that there was "no evidence found on Ms. Berman's computer which suggested that she was extorting Mr. Durst or that she helped cover up anything related to Kathie Durst."

Windham rejected all of the defense motions.

Durst has been behind bars since March 14, 2015, when he was taken into custody in a New Orleans hotel room hours before the airing of the final episode of the six-part HBO documentary series "The Jinx: The Life and Deaths of Robert Durst," which examined the disappearance of Kathie Durst and the shooting deaths of Berman and Black.

During his time on the stand, the defendant told jurors that a bathroom recording of him shown in the series in which he said, "There it is, you're caught," referred to the cadaver note he ultimately admitted writing.

Durst had been confronted by Andrew Jarecki — director and co-producer of "The Jinx" — about the cadaver note and two envelopes addressed to Berman and acknowledged that it was pretty obvious that the handwriting was the same, even though he had denied for years that he had written the note to police about Berman's body.

Durst subsequently admitted that he wrote the letter.

When asked what he meant by his recorded comment "killed them all, of course" that was shown during the series, Durst said, "What I did not say out loud or perhaps I said very softly, `They'll all think I killed them all, of course."'

In his final argument, Deputy District Attorney John Lewin told the jury that there was a "mountain of evidence" against Durst, whom he said "killed three people," and that it is time for Durst to be "held accountable." The prosecutor noted that Durst's wife had mysteriously disappeared never to be seen again, that Berman was killed after telling Durst she was going to talk to police looking into Kathie Durst's disappearance, that Black was killed and dismembered and that a mutual friend of Durst and Berman testified that Durst had told him about Berman, "It was her or me. I had no choice."

Another prosecutor, Habib Balian, told jurors that the killing was "planned" and "premeditated," and that "Susan knew her killer and let him into the house" before being shot in the back of the head when she turned her back.

Balian noted that Durst acknowledged that Berman had told him she was going to speak with police after the investigation was reopened into Kathie Durst's disappearance.

One of Durst's attorneys, David Chesnoff, had urged jurors in his closing argument to acquit the defendant, whom he had described earlier as "sick and elderly."

"They have not proven that Bob Durst killed Susan Berman beyond a reasonable doubt," the defense lawyer said. "Bob did not kill Kathie Durst, therefore there was no great secret ... No evidence is evidence that they haven't proven their case beyond a reasonable doubt."

Chesnoff told jurors Berman did not make a phone call posing as Kathie Durst to the medical school where the missing woman was a student — as the prosecution contends she did to provide an alibi for Durst — and that she "wasn't a witness to anything." The defense attorney contended that the initial investigation by Los Angeles police into Berman's killing was "shoddy and incomplete," and that police didn't even find a fingerprint from Durst even though he acknowledged being near the body of the 55-year-old woman he had met at UCLA years earlier.

"Who else did they miss?" Chesnoff asked. "They missed the real killer ... This was a botched investigation. Now let's blame it all on Bob. That's what we always do and people wonder why Bob Durst was running — because it never stops. You will put a stop to it."

Shortly after the verdict, Kathie Durst's family issued a statement in which they said, "Today, more than ever before, it is clear that she was murdered by Robert Durst in Westchester County, New York, on January 31, 1982. The evidence is overwhelming. Although Durst has now been rightly convicted of killing Susan Berman, who helped him conceal the truth about Kathie's death, the McCormack family is still waiting for justice. Kathie is still waiting for justice. "

"The justice system in Los Angeles has finally served the Berman family. It is now time for Westchester to do the same for the McCormack family and charge Durst for the murder of his wife, Kathie, which occurred almost 40 years ago. They have had interviews, statements and documents for months," the family said in its statement.

The Los Angeles Times reported earlier this month that the Westchester County District Attorney's Office in New York would be convening a grand jury within a few weeks involving the disappearance of Kathie Durst, and that the family's attorney, Robert Abrams, received an email notifying them that her family members will not be permitted to speak at Durst's Los Angeles sentencing.

Durst has long been estranged from his real estate-rich family, which is known for ownership of a series of New York City skyscrapers including an investment in the World Trade Center. He split with the family when his younger brother was placed in charge of the family business, leading to a drawn-out legal battle and ultimately reached a settlement in which the family reportedly paid him $60 million to $65 million.