LOS ANGELES — The first of several women expected to testify that Phil Spector menaced them with a gun took the stand at his murder trial Thursday and recounted a 1993 incident in which the music legend pistol-whipped her twice and ordered her at gunpoint to disrobe.

"I was sobbing. I said to him, 'Why are you doing this, Phil? Why are you doing this?'" Dorothy Melvin testified.

The witness, a former manager for comedian Joan Rivers, told jurors the violence began after Spector consumed most of a fifth of vodka and veered into a rage-filled state she referred to as "Phil mode."

"Phil is a very brilliant and charming man, and you really enjoy him when he is in his charming mode," she said, but when he drinks, "he snaps and he turns on a dime and becomes a lunatic."

Prosecutors seeking a murder conviction for the 2003 shooting of Lana Clarkson contend that the death fits Spector's longstanding pattern of threatening romantic interests with firearms when he is intoxicated. Three and possibly four other women are to testify about additional incidents.

The night Clarkson died, Spector had been drinking heavily. Her body, with a single gunshot wound in her mouth, was found seated on a chair in his foyer, her purse still hanging from her shoulder. His defense contends she shot herself.

Melvin, the first witness to testify in what is expected to be a two-month trial, said she called police to recover her purse from Spector's house, but did not file charges in the assault, which, she said, resulted in a small cut and two welts on her head.

"I didn't want it to become a National Enquirer cover," she said

But from that point on, she refused to be alone with Spector.

"I didn't know if he would turn again," she testified.

Jurors sat rapt as Melvin, a petite brunette woman in a black suit and lacy white shirt, offered an account filled with small details and dramatic flourishes. As she related the screaming exchanges between herself and the defendant, she mimicked his deep, angry tone and her panicked, high-pitched cries.

Spector, resting his chin in his palm, stared at her as she described the incident, which she said began as "a lovely evening."

She said she and Spector danced, shot pool and looked at the music memorabilia in his Pasadena home, which included John Lennon's guitar.

"The most vivid scene is him at the piano with a fifth of vodka," she said.

Melvin, who did not drink that evening, said Spector was taking swigs straight from the bottle. She said as the evening grew late, she fell asleep on the living room couch. When she awakened in the middle of the night, she saw the vodka bottle was drained down to about three inches from the bottom and Spector was gone. She eventually spotted him outside.

"He was standing there pointing a handgun at my brand new little green Mercedes," she said, stretching out both arms and clasping her hands so her index finger was in shape of a gun.

Melvin, who referred to herself as "a markswoman" and said she frequented a gun range in Beverly Hills, recognized the handgun as a snub-nosed revolver.

"He looked over his shoulder and screamed at me to get the 'f' back in the house," Melvin recalled. She said she "stood her ground" and yelled back at him. Suddenly, she testified, he backhanded her with the hand holding the pistol.

"At that point, I knew I was in trouble," she said.