Was arrested in March last year just as HBO aired final episode of 'The Jinx'

Authorities said Durst wanted to keep Berman from talking to investigators looking into the disappearance of his first wife

He is charged in the death of his friend, writer Susan Berman, 16 years ago

Real estate heir Robert Durst pleaded not guilty Monday to murder in the death of a friend 16 years ago.

Authorities have said Durst wanted to keep writer Susan Berman from talking to investigators looking into the disappearance of his first wife.

The 73-year-old Durst entered the plea Monday during a long-awaited appearance in a Los Angeles courtroom in the death of Berman 16 years ago.

Los Angeles County prosecutors have been seeking to bring Durst to California since shortly after his arrest in March 2015.

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Robert Durst wore a neck brace during a long-awaited court appearance in a Los Angeles courtroom Monday (pictured). He pleaded not guilty in the death of Susan Berman

Before he could be brought to California, Durst (pictured with his neck brace Monday in court) faced a federal weapons charge in New Orleans

Durst (pictured in a wheelchair in court Monday) was recorded making what some have interpreted as a confession during the final episode of six-part documentary 'The Jinx'

'I do want to say here and now though I am not guilty. I did not kill Susan Berman,' Durst (pictured in court Monday) said as he entered a not guilty plea

Durst was pictured in a photo published by NBC Los Angeles wearing a neck brace in court Monday.

He arrived in court in a wheelchair and spoke in a hoarse voice.

'I do want to say here and now though I am not guilty. I did not kill Susan Berman,' he said according to the Los Angeles Times.

The arrest came just as the final episode was airing of 'The Jinx', an HBO documentary that featured Durst and examined his alleged ties to the killing of Berman and several other crimes.

Durst was recorded making what some have interpreted as a confession during the final episode of the six-part documentary.

Authorities said Durst (pictured in March 2015) wanted to keep from talking to investigators looking into the disappearance of his first wife

Berman (pictured with Durst), Durst's confidante, was found fatally shot in 2000 inside her home near Los Angeles. She attended UCLA with Durst in the 1960s

Kathleen A Durst (pictured with Durst), Durst's first wife, disappeared aged 29 in 1982 after a weekend in Westchester County. Durst has never been arrested in the case

'What the hell did I do?' Durst whispered to himself while still wearing a microphone. 'Killed them all, of course.'

'There it is, you're caught. What a disaster,' Durst added.

Durst's confidante was found fatally shot in 2000 inside her home near Los Angeles. Berman, the daughter of a mobster, attended UCLA with Durst in the 1960s.

Police reopened the investigation into Durst's first wife disappearance in November 2000, two months before Berman's death.

Kathleen A Durst disappeared aged 29 in 1982 after a weekend in Westchester County. Durst has never been arrested in the case.

The final episode of HBO's 'The Jinx' (pictured) featured him whispering to himself: 'What the hell did I do? Killed them all, of course'

Investigators could never locate her and her family asked a New York judge in April to declare her legally dead.

Before he could be brought to California, Durst faced a federal weapons charge in New Orleans.

He pleaded guilty to that charge in April and has begun serving a seven-year prison sentence. Durst was brought to Los Angeles County jail from a federal prison in Indiana last week.

Durst's attorney has said his client is eager to prove his innocence in Los Angeles.