NEW YORK — Two men seriously injured in a 50-shot police barrage that killed their friend on his wedding day appeared yesterday before a grand jury investigating whether five officers should face criminal charges.Joseph Guzman, 31, and Trent Benefield, 23, were the first of several key witnesses to testify as the investigation of the November 25 shooting that killed an unarmed black man, Sean Bell, draws to a close.

"I got to tell the truth," Guzman said as he left the closed-door session in a wheelchair.

Beginning Monday, the five shooters are expected to be called in ascending order based on the number of shots they fired: Paul Headley, who shot one round; Michael Cary, three; Marc Cooper, four; Gescard Isnora, 11; and Michael Oliver, 31.

Earlier yesterday, Benefield and Guzman prayed on the steps of a courthouse with the Rev. Al Sharpton and the fiance of the dead man before heading to a nearby office building to offer their version of the case, which has outraged African Americans and raised questions about police tactics.

Lawyers for the pair have said they would testify that five shooters never identified themselves as police before opening fire.

Bell was black, as are the other shooting victims. Some of the officers involved are black and some are white.

"We waited through winter to be able to tell the truth," Sharpton said.

A vote on whether the officers could face criminal charges is expected by the middle of the month, lawyers said.

Bell, 23, was killed before dawn after his bachelor party at a topless bar where undercover police were investigating prostitution complaints.

Union representatives and lawyers for the officers have said their clients overheard Bell and his friends argue with another patron and thought they were going to retrieve a gun from a car parked around the corner.

When an undercover detective approached the car — driven by Bell and carrying Benefield and Guzman — it lurched forward and bumped him, then twice rammed into an unmarked police minivan, the NYPD said.

The undercover officer, who has claimed through his lawyer that he spotted one of the men make a suspicious move, squeezed off 11 rounds before the vehicle came to a stop. One of the other plainclothes detectives fired 31 bullets.

All the officers have been taken off undercover duty and put on paid leave.