In the initial hours after Keeven Robinson died following a chase and “brief struggle” with narcotics deputies in a New Orleans suburb Thursday, authorities said his death might have been related to his long medical history of asthma.

An air-quality alert had also warned residents in the area of particularly unhealthy ozone levels that day. But Robinson’s family wasn’t convinced.

And on Monday, the Jefferson Parish coroner said an autopsy confirmed that the death of Robinson, a 22-year-old black man, was a homicide.

The cause of death was “compressional asphyxia,” and an autopsy Saturday revealed “significant traumatic injuries to the neck, the soft tissue of the neck,” the coroner, Gerald Cvitanovich said in a news conference.

The four plainclothes narcotics detectives involved in the arrest have been reassigned to desk work while authorities investigate the death, Jefferson Parish Sheriff Joseph Lopinto said. He did not release the names of the four detectives but said all four are white.

“The reality of it is they were in a fight with this gentleman,” Lopinto said. An investigation will now have to determine whether the detectives were justified in their use of force.

Robinson had been a target of a narcotics investigation, suspected of dealing drugs, Lopinto told re porters last week. He was carrying a white powder substance that Lopinto believed to be heroin.

When he pulled over at a gas station Thursday, Robinson saw the detectives coming and drove away, hitting one of the detectives’ cars on his way out of the station. The detectives, who wore plainclothes but displayed their badges, chased his vehicle for a block until Robinson struck another one of their vehicles. He then took off on foot, jumping over several fences as police ran after him, Lopinto said.

After a “brief struggle” with him, detectives handcuffed Robinson. Then Robinson stopped breathing, Lopinto said. Detectives began administering CPR, and Robinson was transported to a hospital, where he was pronounced dead.

“Somebody’s family actually lost a life, and I’m very cognizant of that,” Lopinto said. “That doesn’t mean our officers did anything wrong, or it may mean that they did something wrong.”

With the investigation ongoing, Lopinto declined to conclude that the detectives used a chokehold during their arrest. “They’re not forbidden from doing that, but they’re not trained … to do that on a normal basis.” He said the detectives have provided statements and are cooperating with the agency. Louisiana State Police will also conduct its own investigation into the death. Lopinto said the FBI’s Civil Rights Task Force will also investigate.

“I understand that this investigation will be under a microscope. I understand it fully,” Lopinto said. “I have every faith in the Jefferson Parish Sheriff’s Office to do their job and to do it correctly. I know they have the expertise,  because this is what they do every day. But I also understand that an independent set of eyes is something that’s appropriate in a case like this.”

Robinson’s death comes amid intense national scrutiny over the treatment of black people at the hands of law enforcement. Jefferson Parish is Louisiana’s largest law enforcement agency, and it has recently been the target of lawsuits accusing narcotics officers of using excessive force, according to the New Orleans Advocate.

Ryan Jackson, who was shot by Jefferson Parish deputies during a drug investigation a year ago, recently filed a federal civil rights lawsuit against the sheriff’s office, the Advocate reported. He said that police used excessive force, causing him to spend a week in a coma and more than a month in the hospital after a deputy shot him with an AR-15 rifle from behind. The four rounds shattered his shoulder blade and sent bullet fragments into his neck and throat.

Local activists and reporters on Monday questioned why the Jefferson Parish Sheriff’s Office has declined to use body cameras on deputies.

“We’ve been discussing body cameras for years,” Lopinto said. But he added that the deputies who arrested Robinson were “undercover” narcotics agents and “would not have a body camera strapped to their chest on a regular basis.”

“I know people would ask for that, but that’s just not the case when you’re working in that capacity,” he said.

The death prompted dozens of family members, local activists and other residents to march the streets Monday night near the site of Robinson’s death. They shouted, “enough is enough” and held signs that read “Justice for Keeven.”

“You got somebody in ‘cuffs, take them to jail,” Robinson’s father, Steven Jackson, told the Times-Picayune. “Why do you think they’re running? They’re scared.”

Gaylor Spiller, president of the Jefferson Parish chapter of the NAACP, said in a news conference that she considers Lopinto a “decent, honorable sheriff.”

“He has not let me down yet, and I don’t feel like he will let me down now,” she said. But she added, “We do recognize and we realize that a lot of our young black African American males and females are dying by the hands of some bad police officers, which makes it look bad on all police officers.”

The attorney representing Robinson’s family, Hester Hilliard, said they are seeking an independent autopsy.

“Today is just as hard as Thursday for this family,” Hilliard said. “They are grieving, and today they had to find out that Keeven lost his life at the hands of another.

“Now it’s time for us to move on to making funeral arrangements for a 22-year-old that should not have died,” she said. “So we ask the public and everyone to pray with this family that they will be strong … and that justice will come for Keeven.”

Robinson was his mother’s only child, the Times-Picayune reported.

Robinson’s grandmother, Sheryl Robinson, said she wants “the young black men to be able to walk the streets.”

“And when the police do press them, we want them to be able to stand and let the police do their job,” Robinson said. “But they’re afraid of the police, they are killing our children.”

When asked for her reaction to the autopsy results, the 61-year-old grandmother said she was not surprised.

“God gave this to me already,” she said. “It just had to be confirmed by the law.”

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