As an exotic dancer at Club Kalua in Queens, Marseilles Payne, 32, spent part of a night performing at Sean Bell’s bachelor party. Then she had the misfortune of watching as Bell’s life ended minutes after he left the strip club.

Yesterday, Ms. Payne, known as “Trini” at the club, told what she knew of the events of November 25, 2006, at 4 a.m. She is the first eyewitness to the killing to testify at the state Supreme Court in Queens in the trial of three detectives charged with firing at Bell and two of his friends.

When Ms. Payne left the club that night, carrying her bag of makeup and bikini outfits, she was on her way to her car. Across from where she was parked, on the other side of the street, Bell, 23, was at the wheel of his car, which also carried two friends. She testified that she knew Bell and his friends not just from dancing for them that night, but from the neighborhood in the Jamaica section of Queens. She had arranged to follow them for a bite to eat at a nearby diner, she said.

Just as Bell pulled away from the curb, she testified, he was hit head-on by a minivan. A “light skinned” man with “dark clothes” got out from the driver’s seat, she said. Standing there, this man began to fire a gun at Bell’s car.

After seeing flame emerge three times from the pistol, Ms. Payne said, “I turned and ran.” She hid in a nearby yard amid bushes.

“I squatted down and put my head in my arms,” she said. The gunfire stopped and she stood up. Then the firing began again and she crouched again, she testified. She offered no more details. Her retelling of the shooting, in which five police officers fired 50 bullets, presented an incident that was far less complex than the one described by both prosecutors and defense attorneys. Most significantly, Ms. Payne said she did not see a second man, Detective Gescard Isnora, standing beside Bell’s car with his gun raised. Both sides agree Detective Isnora, who was working undercover that night, was there.

Ms. Payne’s testimony supports a key claim of prosecutors: that Bell may have never known that the men firing on him were police officers. She said she did not hear the man at the wheel of the minivan, Detective Michael Oliver, say anything as he started shooting. Defense lawyers have said the detectives believed someone in Bell’s party had a gun, and the detectives were trying to make an arrest.

Detectives Oliver and Isnora are charged with manslaughter. A third, Marc Cooper, is charged with reckless endangerment. From the witness stand yesterday, Ms. Payne didn’t indicate that she recognized any of the three men who now sat at the defense table from either the shooting or undercover investigations at Club Kalua.

Ms. Payne no longer works at the club. She is now a medical assistant for the city’s Department of Homeless Services. On the witness stand, dressed in a smock, Ms. Payne spoke broadly about her life. She claimed to have been the second-best pole dancer in the city. Of that talent, she said only: “It is what it is.”

Ms. Payne, a mother of two, told of another tragedy that occurred three weeks before Bell died. Her boyfriend, whom she identified by a first name, Dallas, was shot five times and killed in a dispute over a parking space, she said. On the night of the Bell shooting, strips of white tape were emblazoned on her rear windshield. They carried the message “RIP DALLAS.”

Ms. Payne, with indignation in her voice, told how, after the Bell shooting, police took her to a precinct and held her there until that evening because she wouldn’t initially tell them what she had seen. “I didn’t see anything and I don’t know anything,” she said she told several officers.

Asked about her reticence by a defense attorney, Ms. Payne spoke in her loudest voice yet. “I didn’t want to get involved,” she said. “I’m a single mother trying to get out of the neighborhood, and I didn’t need this drama in my life. This is causing me so much pain.”