Accused murderer Robert Durst testified yesterday that he "must have been out of my mind" when he ran away to Galveston, Texas, donned a wig and posed as a mute woman.

Taking the witness stand, the cross-dressing millionaire said his "life became hell" on Oct. 31, 2000, when he learned there was a new probe into the 1982 disappearance of his first wife, Kathie.

"It seemed like the problem was I was Robert Durst," said the scion of one of New York's leading real-estate families. "I wanted not to be Robert Durst."

Two weeks later, he said, he decided to "go to Galveston and hide."

Why? asked defense attorney Dick DeGuerin.

"I think I must have been out of my mind," he replied in a tired, gravelly voice. "I went to Galveston and disguised myself — to never use the name Robert Durst again, never to see these people again."

Durst, who posed as a mute woman named Dorothy Ciner, said, "I hated wearing the wig. I don't know how women do it."

Once in a bar, he said, he set fire to the wig lighting a cigarette and burned his forehead.

The wig fell off.

"I got off the bar stool, put on the wig and sat back down," he said matter-of-factly.

Another time, at the local library, Durst forgot he was a "she" and walked into the men's room — freaking out a man standing at a urinal.

Explaining why he decided to run away, Durst said he feared that if he was charged in Kathie's disappearance, he would go to jail.

He claimed he was terrified because he spent six hours in a Tijuana (search) cell for buying marijuana when he was 22.

"My teeth chattered and I shivered all six hours until I bailed myself out with my watch," he recalled.

In November 2000, he said, news of a reopened probe into Kathie's death hit the New York papers and reporters and photographers swarmed outside his apartment building.

"It convinced me I wanted to go away and hide and not be Robert Durst," he said. "Nobody was on my side, really. It was to the advantage of the authorities that I be painted black."

Durst said that on Nov. 13, he decided to go to Galveston — without explaining his choice.

He wrote his accountant saying his second wife, Debrah Lee Charatan, should be given the power of attorney over his fortune.

"I won't be coming back," he wrote. "Tell Debbie to take care of my money."

Durst is accused of murdering his elderly neighbor, Morris Black, chopping up his body and dumping the parts into Galveston Bay.

Durst claims he shot Black accidentally as the two were struggling for a gun.

[The Associated Press reported that Durst said he and Black didn't spend much time together until they watched TV and drank Jack Daniels one night at his $300-a-month apartment.

"He sort of took over the remote control," Durst said of Robert Black. "If a commentator came on and he didn't like what he was saying, he would argue with him. He'd talk loudly all the time."]

Though the news accounts said the New York State Police had reopened the probe, Durst again claimed that Westchester County, N.Y., District Attorney Jeanine Pirro (search) had begun a witch hunt against him.

Pirro, he said, "was going to use a new investigation of Robert Durst to further her political career. I believe she wanted to charge me and get publicity to further he political career."

Durst said that in December 2000, he returned to New York, married Charatan and learned that his best friend, Susan Berman (search), had been murdered in Los Angeles.

"Right then and there I had two thoughts: What happened to Susan Berman and I wanted to get away from this Jeanine Pirro lady," he said. "It made me feel scared again."