(Reuters) — Real estate heir Robert Durst testified to chopping up the body of a Texas neighbor he killed in self-defense and to abandoning the body of his best friend after discovering her dead in her Beverly Hills home during his Los Angeles murder trial on Monday.

Testifying in his own defense on the charge of murdering his friend Susan Berman, Durst admitted leaving both crime scenes, each time making an initial attempt to call the 911 emergency number before deciding against it.

But the ailing 78-year-old again denied the crime for which he is on trial – killing Susan Berman in December 2000.

Prosecutors allege Durst killed Berman because she knew too much about the disappearance of his wife two decades before. Durst was never charged for the 1982 disappearance of his wife, Kathleen McCormack Durst.

Police also claim Durst killed his neighbor Morris Black in Texas in 2001 because Black discovered Durst was hiding out there after Berman’s death and after Durst heard reports prosecutors had reopened the investigation into his wife’s disappearance.

A Texas jury acquitted Durst of killing Black after Durst testified it was in self-defense, although Durst admitted to evidence tampering for chopping up his body with an ax and dumping it in Galveston Bay.

With the Los Angeles County Superior Court jury aware of Durst’s past, the defense team again called him to testify, as he has done for several days in a wheelchair and county jail uniform. He later will be subject to cross-examination by prosecutors.

Durst said he discovered Berman’s body in a bedroom after arriving at her home, seeing the back door open, and entering the house.

He said he first tried to call the 911 emergency number from Berman’s line, but the cordless phone was dead. He then drove to a pay phone and called 911 and reached an operator, but hung up rather than give his name. So he wrote a letter instead to police that said only “cadaver” and listed her address, an admission that came after lying about the letter for years.

“Why? Because it’s a very difficult thing to believe. I mean I have difficulty believing it myself. That I would write the letter had I had not killed Susan Berman,” Durst said.

He later took an apartment in Galveston, Texas, where he befriended Black but the relationship became strained after Black fired a gun inside Durst’s apartment, Durst said.

Durst said he came home one day to find Black there, and Durst discovered his gun was missing from its hiding place in the oven. Black had it, Durst said, and as Black wheeled toward him, Durst grabbed the gun, they wrestled to the floor, and the gun went off, hitting Black in the face.

Durst’s defense lawyers re-enacted the scene, wrestling on the floor in their suits and ties, eliciting laughter from the courtroom despite the deadly serious topic.

“That’s a full-service law firm,” Durst said, prompting more laughs.