Murderer who caused 'most chilling end to documentary' after forgetting mic was on left grim 'cadaver note'

A killer who confessed to his crimes on tape after forgetting his microphone was still on left a grim clue for cops after one of his murders.

Taking part in a true crime documentary proved to be Robert Durst's downfall, as the New York-born real estate heir unwittingly incriminated himself during filming.

He managed to get away with murder for decades before he unravelled his own web of deceit by mumbling to himself during a trip to the loo - seemingly forgetting he was mic'd up.

In the damning audio that featured in the 2015 HBO documentary, The Jinx, Durst says: "There it is...I’m caught. What a disaster. What the hell did I do? Killed them all, of course."

The wealthy businessman and son of real estate magnate Seymour Durst made the admission after being confronted with a piece of evidence - a 'cadaver note' - that linked him to one of the murders.

Take a look at the chilling footage here:

Although he routinely denied any involvement, Durst left a trail of death behind him - beginning with the mysterious disappearance of his first wife, Kathleen McCormack, in 1982.

The dental hygienist's body was never found, and although he was suspected of being involved, Durst was never formally charged...until much later on.

Then in December 2000, the property tycoon's unofficial spokesperson and longtime friend, Susan Berman, was found murdered 'execution-style' at her Los Angeles home. The following year, Durst moved to Galveston, Texas, and his neighbour Morris Black was gruesomely killed and dismembered.

But there wasn't any solid evidence to link him to the killings, so by the time The Jinx was made 14 years later, Durst was still a free man.

Robert Durst died in prison at the age of 78 (Jae C. Hong-Pool\Getty Images)

He was arrested the night before the finale of the documentary series - which delved into the deaths of McCormack, Berman and Black - was set to air in 2015.

In this episode of The Jinx, Durst had been confronted with a letter that he had written to his pal Berman a year before her death, alongside one which police had received that was believed to be from her killer.

In wake of her murder, cops received correspondence directing officers to her home, where she was found with a fatal gunshot wound to the back of the head. The note included Berman’s address and the word 'cadaver'.

While shooting The Jinx, Durst denied sending it ,despite the handwriting appearing to perfectly match the other letter he had sent her.

However, bizarrely, he told cameras that 'only the killer could have written' the letter received by authorities.

Looking at both notes, Durst said: "I wrote this one but I did not write the cadaver one," but struggled to tell the difference between the two just seconds later.

He was confronted with the infamous 'cadaver' note while filming The Jinx (Los Angeles County District Attorney's Office)

Following on from this, he headed to the bathroom in what appeared to be a panic and made his notorious mic'd up confession.

And while on trial for his crimes in 2020, Durst finally admitted that he had penned the 'cadaver' note to police, although he didn't believe this proved his guilt. He instead claimed that he had headed to his friend's house and found her dead, rather than pulling the trigger himself.

However, prosecutors argued that he had slain Berman as he feared that she may expose the truth of what happened to his missing wife McCormack, The Guardian reported.

Ultimately, Durst was jailed for life without the possibility of parole for his friend's murder and was formally indicted for McCormack's murder in November 2021, shortly before his death.

He was surprisingly acquitted of Black's killing, which he claimed was an act of self-defence. Durst died behind bars at the age of 78 in 2022.