"He walked up, held the gun to my face between my eyes and said, 'If you try to leave I'm going to kill you,'" Melissa Grosvenor testified Wednesday after another witness said the record producer held her hostage at gunpoint.
Their testimony supported prosecutors' case that Spector had a pattern of pulling guns on female companions leading up to Clarkson's death in the foyer of his suburban mansion. A shot was fired from a gun in her mouth after she went home with him from her job at a nightclub.
Spector's lawyers say Clarkson shot herself.
Grosvenor said she met Spector in New York in 1991 when she was a waitress, found him "very charming, quick-witted," and dated him for a year and a half.
She said after a dinner in Beverly Hills she went back to his house, but when she told Spector around 2 a.m. that she was tired and wanted to go, he left the room and returned with a gun.
"I was shocked. I started crying. ... I was afraid. There was no doubt in my mind if I tried to leave he was going to kill me," Grosvenor said.
She said he holstered the gun and "started walking back and forth, cursing and talking crazy."
Grosvenor said that after the confrontation she fell asleep and the next day Spector did not talk about it. She said after she returned to New York he started asking her out. She said when she declined he left such messages as, "I've got machine guns and I know where you live."
On cross-examination, Grosvenor acknowledged she was convicted of embezzlement in Georgia and later lied on an employment application when asked about a criminal history.
Earlier, music industry photographer Stephanie Jennings testified that Spector threatened her with a gun and held her hostage in a hotel room, forcing her to call 911.
Jennings said she and Spector developed a long-distance relationship in 1994 and the next year she joined him for the Rock and Roll Hall of Fame inductions in New York, where Spector got her a room on his floor of the Carlyle Hotel.
She described being at a party where Spector became "extremely drunk, obnoxious."
She said she went back to her room and slept until a bodyguard knocked and told her Spector wanted her in his room. She said that when she refused, Spector showed up drunk, and in a growing argument he slapped or pushed her, causing her to fall on the toilet. She said she grabbed Spector, who fell into the bathtub.
Spector left, returned with a gun, put a chair in front of the door "and said I wasn't going anywhere," she said.
Jennings said officers responding to the 911 call treated her "as if I was a call girl." She said she didn't press charges.
On cross-examination, defense attorney Roger Rosen suggested Jennings was not as scared as she contended and confronted her with statements she made to sheriff's detectives in 2004.
In the interviews she said she did not feel threatened and continued to date Spector.
Asked about Spector's gun, she said, "I never really thought he was going to use it to kill me. I never thought he was purposely going to use it to kill anyone."
Asked by Rosen if she still contends she feared for her life, she said, "Yes, that's why I called 911."
Spector, 67, rose to fame in the 1960s and '70s, changing rock music with what became known as the "Wall of Sound" recording technique. Clarkson, who was a hostess at the House of Blues when she met Spector, was best known for a 1980s role in Roger Corman's "Barbarian Queen."