By 10, he was such an angry child that a family doctor wrote that Durst might be schizophrenic. But Altschuler says the doctor was simply seeing the signs of Asperger's syndrome.
"Certainly, children who are somewhat autistic, who have Asperger's, do have a great deal of anger. Because they are really being frustrated a great deal," says Altschuler.
Jim McCormick, the brother of Durst's missing wife Kathie, believes that this anger and frustration makes his brother-in-law a dangerous man.
"Devious, deceptive, criminally cunning, contemptuous of civility. This is, you know, the person who doesn't believe any of the rules apply to him," says McCormick, who believes that Durst murdered his sister.
"He was already at his full rage, and she was at her full throttle of womanly independence --and that a terrible, terrible fight ensued."
But the Altmans says Durst has been unfairly accused. "I honest to God think that if there were anything in these accusations, something would have come in the past 20 whatever years," says Emily Altman.
"I think Bob's an easy target, because he's quiet. He's shy. People sometimes interpret that in different ways."
Would being a person who doesn't feel a lot of emotion make him more able than the average person to commit a crime? "No, it makes him, to me, less dangerous," says Altschuler. "Because most people commit crimes because of emotion. Not because of lack of emotion."
Even if Durst dismembered a body? "No," says Altschuler. "Because there's nothing in his history to indicate a real dangerous past."
There is, however, considerable evidence that Durst has been violent in the past.
There's the hair-pulling incident that Kathie's brother remembered witnessing. Durst also kicked in the face a man he believed was involved with his wife. And shortly before Kathie disappeared, she went to a New York hospital with bruises.
Even Altschuler admits that Durst sometimes hit his wife. "He hit her in the stomach. Absolutely, he had. But that was to get her attention," says Altschuler, who claims Durst never meant to hurt Kathie.
Altschuler adds that even though Kathie wanted a divorce and financial settlement, Durst still had no reason to kill her: "Money doesn't mean much to him. He's lived very conservatively. [Even the fact that she wanted to leave him] meant nothing to him. Because after all, he couldn't feel that much of an attachment to her."
"He's not a robot. There is no psychiatric disorder that's a get-out-of-jail-free card, so to speak," says Dr. Lawson Bernstein, a forensic psychiatrist who studied Durst's trial testimony at 48 Hours' request. He believes that Durst suffers from only a very mild form of Asperger's syndrome. "We're talking about someone with Asperger's, who nonetheless forms close human relationships."
Durst, for example, has maintained his friendship with the Altmans. In 2000, just before he fled New York, he got married again, to New York real estate broker Debrah Charatan.
"This is somebody who's been married twice, who does have some ability for human connection," says Bernstein. "If he's capable of normal human interaction, he's capable of feeling emotions. And if he's capable of feeling emotions, he's capable of doing things that human beings do – including murder."
In Christmas 2000, another dead body was discovered – this time in Los Angeles.
The victim was Susan Berman, a flamboyant writer with a storied past. Her father was Davie Berman, one of the pioneer mobsters who founded Las Vegas.
The timing of Berman's death sparked suspicion in people who followed Durst's story. She was shot just a month after newspapers reported that police had re-opened their investigation into the mysterious disappearance of Kathie Durst.
Berman was once Durst's close friend and had been living in New York when Kathie disappeared. Investigators had planned to talk to her, but before they could meet with Berman, she was murdered, shot in the back of the head.
"Susan would not have let anyone into her house. It was someone she knew," says Kathie's friend, Ellen Strauss. She thinks Durst killed Berman because she helped him cover up his wife's murder back in 1982. "She knew too much."
Strauss says that the morning after Kathie disappeared, a woman called her medical school, identifying herself as Kathie, to say she wasn't feeling well. "I think it was Susan Berman who made that call," says Strauss. "I think that's why Susan Berman was killed. Once the story broke about the case re-opening, I think Bob was trying to mop up all the loose ends."
Durst's attorney, Chip Lewis, says Berman's murder was a clear and simple mob hit: "The fact of the matter is Susan Berman had cried out soon before her murder that she was about to expose the mob in a tell-all book about what she knew. It was a hit-style murder."
But sources close to the L.A. investigation say that there wasn't any mob connection -- and that Durst is a focus of the investigation. And when Berman was found murdered in L.A., New York District Attorney Jeanine Pirro, of Westchester County, turned up the heat on the long cold case of Kathie Durst.
"We really didn't get involved in the case until after Susan Berman was shot in Los Angeles," says Pirro.
There are now active murder investigations on both coasts. In Berman's case, Durst denies that he was in Los Angeles, but authorities tell 48 Hours that they have documents which they believe prove that he was in California at the time Berman was killed. Still, no charges have been filed, and Durst's attorneys say it's unfair to jump to conclusions in either the disappearance of his wife or the death of Susan Berman.
Galveston Police Det. Cody Cazalas says there is evidence that Durst has a long history of deceptions: "I think if Bob Durst was to tell me good morning, I'd run outside and see if it's raining."
Long before he dressed as a woman and used false identities in Galveston, Durst had been taking other people's names and Social Security numbers. That's what private detective Bobbi Bacha found after she was hired by a local newspaper in Texas to research Durst.
For example, Bacha says, "We know that Dorothy Ciner is a confirmed name. E Dianne Wynn. We know that he used Kathleen Durst. We know that he used Jezowsky."
During the '80s and '90s, Durst was renting or buying up residences in New Orleans, Dallas and Galveston, as well as several places in New York, San Francisco and Trinidad, Calif.
Durst's attorneys say their client was just trying to escape the burdens of his life. "Bob was not comfortable being Bob Durst," say DeGuerin. "He had to explain that he was extremely wealthy and didn't have to work. He was not proud of that."
"I think he killed his wife in 1982 and disposed of her and he's been living with that, and he's been waiting for the other shoe to drop," says Cazalas. "And when it did, he was gonna run. And he would run all across the country and have safe houses. That's why I think he did it."
Prosecutors have been holding Durst in jail for almost a year on other charges. So how will he manage to get out and around the multi-billion dollar bail?
Durst remains a very wealthy man, but not wealthy enough. He's been in jail for 10 months after his shocking acquittal because he couldn't make bail, which was set at $2 billion.
Even though Durst was acquitted in the murder of Morris Black, he's still facing bail-jumping charges for skipping town before the Galveston murder trial began last fall.
He was on the run for seven weeks. Then his story took a pathetic turn when the wealthy real estate heir was arrested in Pennsylvania trying to shoplift a sandwich from a grocery store. Police say he had two loaded guns, some marijuana and $38,000 in hundred dollar bills. He has been in the Galveston jail ever since.
"It was a product of irrational behavior," says Durst's attorney, Chip Lewis. "He was very tired. He was very suicidal. He was very confused."
"He's probably the wealthiest person in the criminal justice system in America. Why would it surprise anyone that his bail would be the highest," says Judge Susan Criss, who's handling the Durst case. "You're not required to set something they can afford, because if you do have to do that, there should not be a single person in this country who has to sit in jail waiting for their trial."
This past February, Judge Criss raised Durst's bail even higher – to $3 billion – after prosecutors added a new charge.
Bail is set to ensure a defendant appears for trial. And Durst's own lawyers have to admit their client has a history of running. There was also concern in Galveston about releasing a man who admitted to chopping up another man's body.
Two weeks ago, Durst's lawyers persuaded an appellate court to lower his bail to $450,000 dollars. Durst could walk out of jail any day.
However, the jurors who acquitted Durst of murder bristle at the charge that his legal dream team swayed them. They maintain that prosecutors just failed to prove their case of premeditated murder.
If Durst is convicted of the new charges, bail jumping and tampering with evidence, he could be sentenced to up to 20 years in prison. But there is also a chance that he could simply be released for time served.
"Assuming he is released, and has some life, he's gonna have to go some place where nobody knows him," says Durst's attorney, Dick DeGuerin. "And live a quiet existence. That's all he wants to do."
Should people be concerned if Robert Durst is ever freed? "No, ma'am," says Dr. Altschuler. "I would stake my 40 years of practice on that."
"I think that wherever Bob Durst goes, there's a certain wake when he leaves," adds Pirro. "And I think that but for the currents in the Galveston Bay, Morris Black would never have appeared on the radar screen. His body would never have floated up. And he would have disappeared off the face of the earth, just like Kathleen Durst did."
Robert Durst is pursuing legal action of his own in a fight over the family fortune. It's a lawsuit against one of his brothers and a cousin. He says they're trying to stop him from naming his second wife as heir to his share of the family trust fund -- reportedly worth millions of dollars a year.
Meanwhile, Robert Durst remains a millionaire under suspicion and under investigation on both coasts.