Texas Judge in Robert Durst 2003 Murder Trial Believes 'Jinx' Recording Will Be Admitted in Court Judge Susan Criss presided over Robert Durst's 03 trial in Morris Black case.

 -- The Texas judge who presided over Robert Durst’s 2003 trial in the Morris Black murder case believes the alleged confession Durst gives in an audio recording on the HBO series “The Jinx” will be admitted in court.

“I believe that tape will be admissible,” Galveston County Judge Susan Criss told ABC News' “20/20.” “He wasn’t coerced.”

Watch the full story on ABC News' "20/20" tonight at 10 p.m. ET

In a powerful off-camera moment Sunday at the end of the HBO series, Durst tells filmmakers he is going to the bathroom and starts to mutter to himself while he is still wearing a microphone. He is picked up on the mic apparently saying to himself, "There it is. You're caught! ... You're right, of course, but you can't imagine ... Arrest him! ... I don't know what's in the house ... Oh, I want this ... What a disaster ... He was right. I was wrong ... And the burping! I'm having difficulty with the question ... What the hell did I do? Killed them all, of course."

The fact that Durst, 71, was in the bathroom alone when he said it doesn't make a difference, Criss believes.

“There was no expectation of privacy,” she said. “He’s got a mic on ... he contacted them and offered to tell them his story on tape.”

Durst's troubled history with the law, and his suspected involvement in up to three murders, spans the country and goes back more than three decades. Durst was charged in the 2001 killing of his neighbor, Morris Black, in Galveston, Texas, but was found not guilty at a 2003 trial, where Judge Criss presided.

At the time, Durst’s defense attorney, Dick DeGuerin, and his team convinced the jury that Durst killed Black in self-defense, then dismembered him and disposed of Black’s body parts in different garbage bags, then threw the bags into Galvaston Bay, because he said he was afraid authorities wouldn’t believe he acted in self-defense.

But Criss said the butchering of the body suggested Durst had previous experience with dismemberment.

“This looked like someone had done this before,” Criss told "20/20." “The medical examiner testified that the person who cut this body up knew what kind of instrument to use on what bone and what muscle in what part of the body.”

Durst, an heir to a real estate fortune, was most recently arrested over the weekend in connection to the unsolved 2000 slaying of his friend, Susan Berman, who investigators believed may have had information about the 1982 disappearance of his estranged wife, Kathleen Durst. He also faces gun and drug charges in Louisiana related to the items allegedly found when he was arrested, and those charges, in combination with past convictions, could keep Durst locked up for the rest of his life.

Durst's attorneys have maintained he is innocent of the charges and are challenging his arrest.

"I think he's an easy target and everybody's piling on. ... They're gonna find nothing," Dick DeGuerin, the lead attorney on Durst's defense team, told ABC News affiliate KTRK-TV on Thursday. "I think Louisiana and their elected officials want a piece of the publicity pie."

As he awaits trial in Louisiana and California, Durst is on suicide watch in a Louisiana detention center that houses inmates believed to have psychiatric issues. Prosecutors were the ones who pushed for him to be placed in such a facility, saying he has "acute mental health issues."

Durst's legal team said he suffers from a form of Asperger syndrome, an autism spectrum disorder.

But Criss believes he is competent to stand trial again.

“Robert Durst is not the least bit crazy,” she said.