NEW YORK — Three detectives were acquitted Friday in the 50-shot killing of an unarmed groom-to-be on his wedding day, a case that put the NYPD at the center of another dispute involving allegations of excessive firepower.

Scores of police officers surrounded the courthouse to guard against potential chaos, and as news of the verdict spread, many in the crowd began weeping. Others were enraged, swearing and screaming "Murderers! Murderers!" or "KKK!"

Jason DeCrow/AP

Protesters react to the verdict in the Sean Bell case outside of the Queens County Criminal Courts Building Friday

AP

In this undated family photo, Sean Bell and his fiancee Nicole Paultre pose with their daughter.

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Inside the courtroom, spectators gasped. Sean Bell's fiancee immediately walked out of the room; his mother cried.

Bell, a 23-year-old black man, was killed in a hail of gunfire outside a seedy strip club in Queens on Nov. 25, 2006 as he was leaving his bachelor party with two friends. The case ignited the emotions of people across the city and led to widespread protests among those who felt the officers used unnecessary force.

Officers Michael Oliver, 36, and Gescard Isnora, 29, stood trial for manslaughter while Officer Marc Cooper, 40, was charged with reckless endangerment. Two other shooters weren't charged. Oliver squeezed off 31 shots; Isnora fired 11 rounds; and Cooper shot four times.

The case brought back painful memories of other NYPD shootings, such as the 1999 shooting of Amadou Diallo — an African immigrant who was gunned down in a hail of 41 bullets by police officers who mistook his wallet for a gun. The acquittal of the officers in that case created a storm of protest, with hundreds arrested after taking to the streets in demonstration.

Though emotions ran high, there were no immediate problems outside the courthouse Friday, where many wore buttons with Bell's picture or held signs saying "Justice for Sean Bell." Some people approached police after the verdict was read, but they were held back and the jostling died down quickly.

William Hardgraves, 48, an electrician from Harlem, brought his 12-year-old son and 23-year-old daughter to hear the verdict. "I hoped it would be different this time. They shot him 50 times," Hardgraves said. "But of course, it wasn't."

The officers, complaining that pretrial publicity had unfairly painted them as cold-blooded killers, opted to have the judge decide the case rather than a jury.

The judge, Justice Arthur Cooperman, indicated when he delivered the verdict that the officers' version of events was more credible than the victims' version. "The people have not proved beyond a reasonable doubt that each defendant was not justified" in firing, he said.

Hours later, the officers appeared at a news conference.

"I'd like to say sorry to the Bell family for the tragedy," Cooper said, thanking God, his lawyers and the police officers who supported him.

The U.S. attorney's office said after the verdict that it had been monitoring the state's prosecution and would conduct an independent review of the case. The Rev. Al Sharpton, who represents Bell's family, called for a federal investigation.

"This verdict is one round down, but the fight is far from over," Sharpton said on his radio show. "What we saw in court today was not a miscarriage of justice. Justice didn't miscarry. This was an abortion of justice."

Michael Palladino, president of the Detectives Endowment Association, responded angrily to Sharpton's suggestion that the verdicts were unfair.

"That's despicable for him to say that because we have the greatest criminal justice system on earth," he said.

The nearly two-month trial was marked by deeply divergent accounts of the night.

The defense painted the victims as drunken thugs who the officers believed were armed and dangerous. Prosecutors sought to convince the judge that the victims had been minding their own business, and that the officers were inept, trigger-happy aggressors.

Both sides were consistent on one point: The utter chaos surrounding the last moments of Bell's life.

"It happened so quick," Isnora said in grand jury testimony. "It was like the last thing I ever wanted to do."

Bell's companions — Trent Benefield and Joseph Guzman — offered dramatic testimony. Both were wounded in the shooting; Guzman still has four bullets lodged in his body.

Referring to Isnora, Guzman said, "This dude is shooting like he's crazy, like he's out of his mind."

The victims and shooters were set on a fateful collision course by a pair of innocuous decisions: Bell's to have a last-minute bachelor party at Kalua Cabaret, and the undercover detectives' to investigate reports of prostitution at the club.

As the club closed around 4 a.m., Sanchez and Isnora claimed they overheard Bell and his friends first flirt with women, then taunt a stranger who responded by putting his right hand in his pocket as if he had a gun. Guzman, they testified, said, "Yo, go get my gun" — something Bell's friends denied.

Isnora said he decided to arm himself, call for backup — "It's getting hot," he told his supervisor — and tail Bell, Guzman and Benefield as they went around the corner and got into Bell's car. He claimed that after warning the men to halt, Bell pulled away, bumped him and rammed an unmarked police van that converged on the scene with Oliver at the wheel. The detective also alleged that Guzman made a sudden move as if he were reaching for a gun.

Guzman said Isnora "appeared out of nowhere" with a gun drawn and shot him in the shoulder — the first of 16 shots to enter his body.

"That's all there was — gunfire," he said. "There wasn't nothing else."

With tires screeching, glass breaking and bullets flying, the officers claimed that they believed they were the ones under fire. Oliver responded by emptying his semiautomatic pistol, reloading, and emptying it again, as the supervisor sought cover.

The truth emerged when the smoke cleared: There was no weapon inside Bell's blood-splattered car.