More than three years after Ronald Greene died in the custody of the Louisiana State Police, five law enforcement officers were charged on Thursday in connection with the violent encounter captured on video, in which Mr. Greene, a Black man, was put in a chokehold and punched repeatedly by officers as he cried out for help.

The charges — which include a single count of negligent homicide for one of the five officers — came from an indictment handed up by a state grand jury in Louisiana, officials and lawyers for Mr. Greene’s family said.

The charges are the first to emerge in a case that has mobilized activists and drawn widespread scrutiny of the state police, as an initial description of Mr. Greene resisting arrest after a high-speed chase was unraveled by body-camera footage. The video, obtained by The Associated Press, showed Mr. Greene, 49, yelling, “I’m scared!” as a white officer repeatedly stunned him with a Taser.

“They need to be held accountable,” Mona Hardin, Mr. Greene’s mother, told reporters on Thursday after the charges were announced, describing the development as a positive step that must be followed up with successful prosecutions. “Because if not, you’re condoning the killing of Ronald Greene. You’re OK with my son being murdered if you just give a slap on the wrist.”

The state police said on Thursday that two troopers had been placed on administrative leave because of the indictment. One of them, Master Trooper Kory York, was charged with the most serious offenses, including negligent homicide and 10 counts of malfeasance in office. (Trooper York had previously received a 50-hour suspension and returned to active duty.) The other, Lt. John Clary, who was charged with malfeasance in office and obstruction of justice, was the highest-ranking trooper at the scene.

Two others with the state police, Trooper Dakota DeMoss and Capt. John Peters, were both charged with obstruction of justice. Christopher Harpin, a Union Parish sheriff’s deputy, was also named in the indictment, charged with three counts of malfeasance in office.

Trooper DeMoss was placed on leave last year after he was arrested in an unrelated case, in which he and three other troopers were charged with using excessive force and deactivating body cameras during arrests.

The five officers charged on Thursday and their lawyers could not be immediately reached for comment. But lawyers representing Trooper York and Deputy Harpin told The Associated Press on Thursday night that they expected their clients would be found not guilty, if their cases reached trial.

Another trooper involved in the arrest, Chris Hollingsworth, was killed in a single-vehicle highway crash in 2020. The Associated Press reported at the time that he had been notified hours earlier that he would be fired for his part in Mr. Greene’s fatal arrest.

“Today’s indictments followed a thorough and extensive investigation by state and federal agencies,” Col. Lamar A. Davis, the superintendent of the Louisiana State Police, said in a statement on Thursday. “Any instance of excessive force jeopardizes public safety and is a danger to our communities. These actions are inexcusable and have no place in professional public safety services.”

Mr. Greene, of Monroe, La., had been pulled over just after midnight on May 10, 2019, by state troopers in Union Parish, east of Shreveport in northern Louisiana. The authorities initially said that Mr. Greene had been pursued by troopers because of a traffic violation and that he had refused to stop and resisted arrest. His death was ruled accidental and was attributed to cardiac arrest by the Union Parish coroner.

Two years later, The Associated Press published the body-camera footage, which showed a starkly different version of events. In the video, Mr. Greene is beaten, held in a chokehold and left handcuffed and face down for more than nine minutes. His family commissioned its own autopsy, which found that he had sustained severe injuries to his skull and had wounds on his face.

The harrowing footage catapulted Mr. Greene’s case, which had drawn little notice at the outset, to national prominence as tensions flared over a series of high-profile cases in recent years of Black men dying in encounters with the police.

The surge of attention led to a tangle of overlapping investigations on the state and federal level. The State Legislature convened a special committee to examine the case and its handling by the state police and elected officials. In 2020, federal investigators opened a civil rights inquiry. In June, the Justice Department announced that it had initiated a broader investigation into the Louisiana State Police over accusations of officers engaging in abusive and discriminatory behavior.

Colonel Davis said on Thursday that the case had already spurred “fundamental improvements to our operations, training and administration” inside the state police.

The case reached the grand jury in November, brought by John Belton, the district attorney for Union Parish. Mr. Belton had said that federal prosecutors did not object to him moving forward with the case.

“This is a victory, and we’re going to take it — and we’re grateful for it,” Meghan Matt, a staff attorney with the American Civil Liberties Union of Louisiana, said at the news conference on Thursday, standing beside Ms. Hardin and other relatives. “But we will continue our relentless pursuit of accountability for these officers and everyone that was implicated in these crimes.”

Yet Ms. Matt said that Mr. Greene’s death left a painful void in his family, one that was particularly pronounced as Christmas approached. Mr. Greene, a barber, was on his way to meet his wife in Florida when the police pulled him over. And he reportedly had gone into remission after fighting cancer for two years.

“For three and a half years, this has been their life,” Ron Haley, a lawyer for the family, said of the persistent effort to “make sure that their son, their brother, their father, their cousin, their nephew, their friend, received justice.”

C. Denise Marcelle, a state lawmaker, praised the charges but also said that the blame extended beyond those officers. “I don’t want to stop at the five,” she said at the news conference.

“I want us to get to the root of everybody who played a part in this cover-up,” said Ms. Marcelle, a Democrat from Baton Rouge serving on the special committee investigating Mr. Greene’s death. “We’ve got to dive into this thing and clean house.”