LAWRENCE, Mass. (Court TV) — Transvestite dermatologist Richard Sharpe told jurors Friday that a vague "compulsion" to save his marriage led him to take a loaded gun to his estranged wife's home.

But on his second day on the stand in his insanity defense murder trial, the millionaire physician testified that a toxic combination of prescription drugs, alcohol and emotional strain the night of Karen Sharpe's death left him unable to remember details of the shooting or explain why he gunned down the mother of his three children.

"I have no idea what the hell was going through my mind. I really don't," Sharpe said.

Sharpe, 47, does not dispute killing his wife of 26 years as she stood in the foyer of the "dream home" where they had once planned to retire. The Harvard-trained doctor contends years of childhood abuse left him insane the night of the shooting. If the jury rejects the insanity defense, Sharpe faces life in prison without parole.

The prosecution claims that Sharpe was furious with his wife for leaving him and taking his money, and prosecutor Robert Weiner dug into the doctor's claim that the incident was a "blur" and a "fog" during a short, but tightly focused, cross-examination.

"You went up there because you wanted to kill Karen Sharpe," Weiner charged.

"I loved Karen," Sharpe replied, matting down his shoulder-length brown hair with his hands and squeezing his eyes shut behind his gold-rimmed glasses.

"You wanted to kill her," Weiner shot back.

"No, I didn't," Sharpe said softly.

On his second day on the stand, the doctor revealed more about his penchant for cross-dressing, a practice he began as a young teen. He said he dressed in full drag a half dozen times, but donned women's underwear or clothes hundreds of times.

"At times, it relaxed me. At times, I thought it was fun and, at times, I thought it was erotic," he said. "Karen and I would sort of use that as a way of playing together."

He acknowledged taking female hormones to "relieve stress," and said he donned his wife's apparel but preferred that of his eldest daughter, Shannon, 28, because it "fit better." He also said he had undergone about six cosmetic surgeries, including "love handle liposuction," a nose job and the removal of hair on his face and legs.

As during Sharpe's Thursday testimony, two male jurors stared away from the defendant during his testimony, but the entire panel was riveted by his account of the shooting and the events leading up to it. Sharpe testified that his life became a "wreck" after Karen Sharpe moved out of their Gloucester home with their two young children, Michael, now 9, and Alexandra, 5, and announced plans for divorce.

Sharpe said he was convinced that she was having an affair with a contractor on their new home in neighboring Wenham. He recalled sneaking up on the home, peering in the windows and discovering the pair and her children in the living room. He said he was furious and broke the headlights on the man's car.

Under questioning from defense lawyer Juliane Balliro, Sharpe ticked off a list of what Balliro termed "major emotional disturbances," including health problems from a fall, the restraining order obtained by Karen Sharpe and her decision to sell off their stocks at a loss of more than $2 million. A defense psychiatrist is expected to testify Monday that he was insane.

"I was a wreck. I couldn't deal with it. I was crying all the time. I couldn't see patients," he said.

Sharpe said that on July 14, 2000, he went with his then lover, Paula Hiltz, to dinner where he consumed "more than one" glass of red wine. Hiltz estimated he drank eight glasses of merlot. Sharpe noted that he was taking six different prescription drugs, including the painkiller Percocet, two antidepressants and a muscle relaxer. After dinner and dancing at a bar, they went to her ex-boyfriend's home to close windows, Sharpe said, and he stole a gun and ammunition lying nearby.

"I don't know why exactly, but I had this desire to get my family back, this desire to go home, this compulsion to go home," said Sharpe.

After Hiltz left, he said, he drove to his wife's home in Wenham eight miles away. He said he loaded the gun and walked to the front porch and opened the door. Prosecution witnesses testified that Karen Sharpe's brother and his girlfriend as well as a babysitter were in the foyer.

"I believe Karen said, 'I'll call the police,' and she held up a piece of paper," said Sharpe, adding that he thought it was the restraining order.

"What do you remember next?" asked Balliro.

"The gun going off," said Sharpe.

He said the noise jarred him, he fled and disposed of the gun along the highway. The weapon has never been found and remains a mystery in the case. Hiltz's ex-boyfriend, Alden Tarr Jr., maintains the weapon missing from his collection was a .30-caliber rifle, but a police ballistics expert testified the murder weapon was a .22-calibre gun. If Sharpe had a weapon before the night of the shooting, it might suggest premeditation.

He said the next 30 hours, before his arrest in a New Hampshire motel, were a blur. At one point, he said, he bought a six-pack of beer and a clothesline in hopes of getting enough courage to kill himself. In the end, he said, he could not find anything strong enough to hold a noose.

Balliro's softball questions gave way to a tough grilling by prosecutor Weiner. He got Sharpe to admit he had lied under oath before when he signed legal papers denying ever striking his wife and filling out medical records indicating only minor psychiatric problems.

"Are you telling this jury that when there is some secondary gain to be had you will lie under oath?" asked Weiner.

After some hedging, Sharpe admitted, "Yes."

The prosecutor also highlighted physical attacks Sharpe made on his wife. He pointed to one 1991 incident where he struck his wife in the forehead with a fork and a New Year's Eve where he hit her so hard she went to the emergency room with a loose tooth.

When Weiner pressed Sharpe on details of the shooting, such as the route he took, Sharpe repeatedly said he could not recall, prompting the prosecutor to point to various complicated business discussions the doctor had the day before the shooting.

"Why can you remember some things, but not others?" the prosecutors asked.

The prosecutor also got Sharpe to admit that he had drawn up a plan to escape from prison during a doctor's visit. Although Sharpe acknowledged that he had discussed the plan with a friend, he called it a "fantasy" he had created when he discovered that, even if found not guilty, he could be held in a psychiatric facility for life.

In perhaps the most dramatic moment, Weiner took the list of "major emotional disturbances" Balliro had displayed on an easel for the jury and one by one asked if they had existed weeks before the shooting when the doctor had spied on his wife and the contractor. With each "yes," Weiner drew a line through the listed problem.

The prosecution reopened its case briefly late Friday afternoon, but to devastating effect for the defense. Psychiatrist Gilbert Bogen, who treated Sharpe shortly after his arrest, said the doctor behaved normally when watching television or talking on the phone, but became affected and strange in one-on-one conversations.

"He would close his eyes squinting, taking on a pained expression," Bogen told jurors, who had just watched six hours of Sharpe squinting and looking pained. "It is my opinion he was malingering."