[Warning: This article contains spoilers from the finale of The Jinx. Read at your own risk!]

On the finale of HBO's The Jinx, suspected killer Robert Durst appears to have confessed to three murders - but will it be admissible in court?

Durst, who was arrested in New Orleans on murder charges Saturday (the day before the finale aired) had been cooperating with Jinx producers Andrew Jarecki and MarcSmerling as they looked into the deaths of Durst's close friend Susan Berman in 2000 and neighbor Morris Black in 2001, as well as the 1982 disappearance of his wife Kathleen.

During one interview with Smerling and Jarecki that aired during Sunday's finale, Durst excused himself to use the bathroom, not realizing that his microphone was still recording. "What the hell did I do?" Durst is heard mumbling to himself in the restroom. "Killed them all, of course."

Robert Durst, subject of HBO's The Jinx, arrested on murder charges

It's unclear whether the recording can be used as evidence in a trial, however, since Durst believed that he was making private comments to himself at the time. Smerling and Jarecki say they didn't discover that audio until two years after the interview took place.

The producers also unearthed a letter Durst wrote to Berman, which a handwriting expert told them matched the handwriting on an anonymous note that was sent to police in Beverly Hills informing them where they could find Berman's body. But, with the documentary in mind, they debated what to do with the information. "We said, if we go to the authorities now, we're missing the opportunity for us to get the real story from him," Jarecki said on Good Morning America Monday.

Smerling and Jarecki finally decided to begin working with law enforcement officials in 2013. "We had a moral obligation and an obligation to the families of the dead to see that justice was done," Smerling told the New York Times.

Smerling and Jarecki said they had nothing to do with the timing of Durst's arrest and "had no idea" that he was going to be taken into custody the day before the finale aired.

Watch Jarecki's Good Morning America interview here:

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