The surrenders today of three police officers indicted in the shooting of Sean Bell will be but the opening scene in a legal drama not seen in New York since the shooting of Amadou Diallo, a contest that could last for years and affect policy and community relations throughout the city.

The officers today will have their mug shots taken and fingerprints documented before being charged with crimes that could put at least two of the men in jail for several years if they are convicted.

The indictments come 115 days after Bell, an unarmed man celebrating his bachelor party with friends at a strip club in Jamaica, Queens, was fatally shot by a litany of 50 bullets, which have been described by different parties in this case as justified, as mistaken, and as murderous.

The final determination will now come before a jury.

“It’s an unfortunate drama,” a professor of police strategies at John Jay College of Criminal Justice, Eli Silverman, said. “I guess you could say the indictment was a prologue and the announcement is the beginning of the first act … The public is going to get the case of characters on all sides.”

Bell was, by many accounts, a young man trying to make sense of his life after run-ins with the law. The shooting canceled a wedding scheduled just hours later and left two daughters without a father.

On Friday, the majority of grand jurors decided that the decisions of three of the police officers who ended Bell’s life amounted to criminality. The official charges will be unsealed this morning, but defense attorneys and other officials leaked that Gescard Isnora, who was working undercover and fired the first shot, and Michael Oliver, who fired a full clip before reloading and firing again, will be charged with manslaughter. A third detective, Marc Cooper, will be charged with reckless endangerment, they said.

Paul Headley and Michael Carey, who fired four bullets between them, were not charged.

The indictments come at a time of low crime but also of heightened awareness of the perils of policing. Two auxiliary police officers were buried this weekend after they were fatally shot in Greenwich Village on Wednesday night. The night before that, one officer was shot and wounded in Harlem and another was stabbed through the skull in Brooklyn. Another officer had his arm broken, and yet another was thrown through a window in TriBeCa.

This all took place in a 48-hour period at the height of the Queens grand jury deliberations.

Already the Bell shooting has set in motion review processes that could change policing in the years to come. The police commissioner, Raymond Kelly, has hired the RAND Corp. to study firearms training and the way the department determines whether a shooting is justified. He also hired the nonprofit organization to study the department’s stop-and-frisk procedures and training.

“It has major repercussions on the New York Police Department,” a police historian and former head of the Citizen’s Crime Commission, Thomas Reppetto, said, adding that Bell’s name had now joined the ranks of Diallo, Abner Louima, and Ousmane Zongo. All these victims of police were young black men, a fact that has fueled allegations by activists such as the Reverend Al Sharpton that the police department holds black life at a lower value than other races. Mayor Bloomberg has said the shooting “appeared excessive.” Mr. Kelly has said that Mr. Isnora’s decision to attempt to arrest the men after being undercover for hours was “unusual.” Undercover officers usually call in backup to make arrests.

Bell’s mother and other relatives, as well as his fiancée, Nicole Paultre-Bell, have said what happened that night was a singular tragedy, not evidence of widespread racism.

An indictment in a police shooting case does not always lead to a conviction. In the shooting of Diallo, defense attorneys moved to change the venue to Albany, where a jury acquitted the officers. A Democratic candidate for mayor, Fernando Ferrer, later said the officers, who had been charged with second-degree murder, were “overindicted.”

The lawyers could argue that Mr. Bloomberg’s statement and the publicity surrounding the case might make a change of venue necessary for the defendants to find a jury that could give them a fair trial.