'Chilling' Robert Durst audio from 'The Jinx' went unheard for three years

The director of HBO's docu-series "The Jinx: The Life and Deaths of Robert Durst" discussed the shocking final moments of the show's finale, and explained that at first, Durst's chilling confession went unheard.

Over the course of the past few years, director Andrew Jarecki and his crew have been conducting interviews with real estate heir Robert Durst, who's faced scrutiny for his involvement in three murders dating back to 1982.

Three years after his last interview with Durst, Jarecki's editors found something.

"There it is. You're caught," Durst was heard saying to himself off-camera. "What the hell did I do? Killed them all, of course."

Jarecki sat down with "Good Morning America" to discuss Durst's apparent admission to the murders.

"I sat there in the edit room with my partners, [Marc Smerling and Zac Stuart-Pontier], and we just sort of shook our heads and it took a while to really understand the impact of it," Jarecki said. "It was so chilling to hear it. It's disturbing to hear it. It makes you very uncomfortable to hear it."

The 71-year-old was arrested in New Orleans the day before the series finale aired Sunday night, but it looks like the timing may have just been a coincidence. Jarecki added he'd been in contact with authorities for the past two years, but had no idea of the timing of the arrest.

The Los Angeles Police Department released a statement saying they had been investigating Durst's involvement in the death of friend Susan Berman since her body was discovered in 2000.

"As a result of investigative leads and additional evidence that has come to light in the past year, investigators have identified Robert Durst as the person responsible for Ms. Berman's death," the LAPD said.

It's believed Durst killed Berman because she had information that could prove he killed his first wife, Kathleen Durst, in 1982. In addition to those two murders, Durst was charged and cleared in the 2001 killing of his neighbor, Morris Black.

Durst's brother Douglas said in a statement,"We are relieved and also grateful to everyone who assisted in the arrest of Robert Durst. We hope he will finally be held accountable for all he has done."

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Robert Durst arrested In New Orleans over cold case slaying