Transcript for Murder Investigation Reopened As HBO's 'The Jinx' Airs
There are new things to report in the long-running case of Robert durst. He is the eccentric New York fortune. He's only been charged of murder once. He decided to participate in a new documentary, and that could be a game changer. Nobody tells the whole truth. Reporter: He is an heir to a billion dollar real estate fortune who's been under a cloud of suspicion for three different murders in three different states over the course of more than 30 years. There are a lot of people out there who think that I killed my wife, that I killed Susan burrman, that I intentionally murdered Morris black. Reporter: And now for the first time, after years of steadfast silence, Robert durst is telling his side of the story. That is a, I would think, if I was as familiar with the media as I am about me. Reporter: It's a new HBO documentary called "The jinx." It's over about 30 years, he's been approached by everybody about telling his story. And he said there's no reason to do it. Reporter: Durst entrusted his story to him because he had earlier made a feature film called "All good things" starring Ryan gosling. He recently sat down with George stephanopoulos. I think after he saw the film and saw that at least we painting a picture of a human being as opposed to a headline, he felt more comfortable. Reporter: There's been a public of fascination since his beautiful wife mysteriously vanished in 1982. Very outgoing and social. Got along with people real good. She was perfect. I don't get along with people. Most people don't get along with me. Reporter: He was never charged in her disappearance. But allegations of domestic abuse fueled rumors that he was involved. Friends said Kathleen was afraid of her husband. Oftentimes she would ask me to drive into the city to stay with her at her apartment, because she was in fear. She didn't know what was going to happen next. Towards the end, I mean, she had showed me bruises on her arm, that she said that he caused. Reporter: But she never filed a complaint against her husband. Did you have anything to do with the death of your wife? I don't know that she's dead. Reporter: Do you think it's possible that she's alive now? It's possible. Not likely. It's not what I think. I think she's almost definitely dead. But I don't know that she's dead. Reporter: She was officially declared dead in 2001. The question is, did the police suspect him enough? And many of her friends and family members think that they could have and should have been tougher in their investigation of him. Shortly before that in the year 2000 another mysterious death, this time of durst's good friend Susan burrman, found murdered in her home in California. I felt terrible for Susan. I was astonished that they were putting all this together that I did it or I caused it to be done. Reporter: Burrman was about to talk to authorities in new York state about what she knew about the disappearance of durst's first wife. The suspicion always was that Susan burrman had information about the death of durst's wife and that durst may have killed her to shut her up. Again, durst was never charged. After burrman was killed, durst moved to Texas, disguising himself as a woman. Then a gruesome discovery. A fisherman in galveston bay found a trash bag washed up on the shore. I was shocked to see it was just a torso. No head, no arms. It was a male, a clean cut. Reporter: Later in another bag the arms and legs found. The head still missing. The victim, a 71-year-old man named Morris black, Robert durst's neighbor. Durst was arrested, but not knowing that he had access to million, the authorities set his bail at $250,000. He was quickly wired the money and then took off. But was your intention when you put up the $250,000 to runaway? Oh, good-bye $250,000. Good-bye jail, I'm out. Reporter: More than a month later he was captured in a small town in Pennsylvania. Where he was caught stealing a hoagy sandwich. Reporter: At his murder trial he admitted to murdering Morris black and dismembering the body, but he claims he was in self-defense. He claimed that the dismemberment was some kind of panic. That he got in a fight. The gun had gone off. We the jury find the defendant not guilty. Reporter: He was acquitted of murder in a verdict that shocked the country, but he was sentenced to five years in jail for evidence tampering and jumping bond. The jurors said they didn't really believe his testimony, but somehow they still acquitted him saying they didn't think there was proof beyond a reasonable doubt. Reporter: He was paroled in 2005 and lived mostly out of the public eye until he decided to participate in the making of "The jinx." You know, I met with bob and his lawyer in New York not long after bob had first contacted me. And his lawyer said I think this is a terrible idea. You've been wrongly accused of three murders over 30 years. There is nothing that sitting down with a film maker is going to do to improve his life. Reporter: Recently authorities in Los Angeles reopened their investigation into the murder of Susan burrman in the year 2000. And this past Sunday showed the discovery of a potentially blockbuster piece of evidence. Her stepson shows a letter that was sent from durst to Susan burrman several months before the murder. The letter appears eerily similar to an anonymous note San Antonio police the D-- sent to mission the day she died. It is exactly the same down to the misspelling of Beverly. That in itself could be enough to convict him of murder. Did you have anything to do with Susan Berman's death? I had nothing to do with Susan Berman's death. Did you have any theory yourself of what might have happened to Susan? No. Reporter: ABC reached out to Robert durst through his attorney, but they have no comment at this time. As for all the renewed interest in the unsolved murders? Well, I think that what the audience will find when they get to the end of this is that they're not scratching their heads. When they get to the end of six episodes, they will know what happened. And this Sunday, in the final episode of "The jinx", he will confront Robert durst with the new evidence.
This transcript has been automatically generated and may not be 100% accurate.