A prosecutor in the trial of three undercover detectives charged in the death of unarmed man on his wedding day said Monday that the shooting can't be explained "as a mere accident or mistake."

But a defense lawyer for one of the officers told the judge in opening statements he would offer evidence showing that Sean Bell was drunk and "out of control" when he left the strip club where he was celebrating his bachelor's party with friends.

Bell died in a hail of 50 police bullets in a case that ignited debate over excessive force and police conduct. State Supreme Court Justice Arthur J. Cooperman will decide the officers' fate, after the defense waived its right to a jury trial.

Outside the courthouse in Queens, a handful of noisy protesters chanted and banged on drums to show their support for the shooting victims and Bell's family.

Nicole Paultre-Bell, who legally took her fiance's name after his death, stopped to pray with Joseph Guzman, a friend of Bell's who was also shot that night, and the Rev. Al Sharpton before going inside. She was scheduled to testify on Monday.

Detectives Gescard Isnora and Michael Oliver are charged with manslaughter while Detective Mark Cooper is on trial for reckless endangerment in the Nov. 25, 2006, shooting.

In his opening statement, Assistant District Attorney Charles Testagrossa said the police vice operation at the Queens strip club where Bell's bachelor party was held was "haphazard at best."

Testagrossa said Isnora, who fired 11 of the shots, failed to display his badge and wait for backup, and gave contradictory orders to Bell and his friends.

He said that once the evidence is heard, "It will be clear that what happened cannot be explained away as a mere accident or mistake."

The prosecutor also said Oliver would have found there was no threat if he had "paused to reassess" while firing 31 of the shots.

But defense lawyer James Culleton estimated that it took as little as nine seconds for Oliver to fire the 31 rounds from his semiautomatic pistol — even with reloading — leaving him no time to reassess.

Culleton said Oliver saw Bell's car trying to flee, then heard Isnora yell, "He's got a gun! He's got a gun!"

The defense lawyer said Oliver will testify that during the chaos, he saw Guzman starting to lift his arms. Culleton said Oliver was convinced that if he hesitated, "He'd be looking down the barrel of a gun and he'd be a dead man."

Investigators found no gun at the scene.

Isnora's attorney, Anthony Ricco, said there was evidence that Bell was drunk and "out of control" when he left the club. Witnesses overheard Bell exchange curses with another patron, and heard Guzman say to someone, "Go get my gat," slang for gun, Ricco said.

Rico said Bell, at Guzman's urging, "tried to run over" Isnora. The lawyer described the car as a "deadly weapon" and "human battering ram."

"When there is a confluence of alcohol and ignorance, there's always a tragedy," Ricco said.

Prosecutors said the third officer, Cooper, fired wildly, with one of his four shots hitting an elevated airport train station. Attorney Paul Martin said Cooper, like his co-defendants, had never fired his weapon before the Bell incident.

"He doesn't even belong in this courtroom for this situation," the lawyer said of Cooper.