Two of the five police officers under investigation by a Queens grand jury testified yesterday about a 50-shot fusillade that killed an unarmed man on his wedding day.

Detective Paul Headley left the closed-door session feeling “relieved that he had the opportunity to tell his version of events,” said his attorney, John Arlia. “Clearly, it has been a toll on him and his family.”

Mr. Headley, 35, dressed in a dark suit, did not speak to reporters after testifying for more than two hours about the killing of Sean Bell. Officer Michael Carey, 26, arrived a short time later accompanied by Patrick Lynch, president of the Patrolmen’s Benevolent Association.

“He will go in there and tell his story as a police officer and put some facts to some of the fiction that ran on the streets,” Mr. Lynch said.

Carey testified for about 90 minutes before leaving with his lawyer, Stephen Worth.

The grand jury has been calling the officers in ascending order, based on the number of bullets they fired: Headley fired one round; Carey, three; Marc Cooper, four; Gescard Isnora, 11; and Michael Oliver, 31.

The officers’ testimony is expected to take the entire week, meaning that a vote on whether or not they should face criminal charges could come sometime in mid-March, lawyers said.

Last week, the grand jury heard accounts from the two surviving victims — Joseph Guzman, 31, and Trent Benefield, 23 — one in a wheelchair and one on crutches, making plain the extent of their injuries.

Mr. Guzman, Mr. Benefield and Bell’s fiance, Nicole Paultre Bell, appeared on the courthouse steps Friday with the Rev. Al Sharpton before they testified about the fatal shooting of Bell on Nov. 25, 2006 — a case that sparked outrage and raised questions about police tactics. The men claim the officers never identified themselves as police before opening fire.

Bell, 23, was killed before dawn after his bachelor party at Kalua Cabaret, a topless bar in Queens.

The grand jury’s investigation began in January. The Queens district attorney’s office has declined to discuss the case.

Union representatives and lawyers for the officers have said their clients became convinced Bell and his friends were going to retrieve a gun from a car parked around the corner after overhearing them argue with another patron.

When Mr. Isnora approached the car — driven by Bell and carrying Mr. Benefield and Mr. Guzman — it lurched forward and bumped him, then twice rammed into an unmarked police minivan, the NYPD said. The undercover detective has claimed through his lawyer that he spotted one of the men make a suspicious move, starting the shooting.

Bell was black, as are the other shooting victims.