Mr. Sharpton has delivered remarks at the funerals of Mr. Floyd, whose 2020 death after an officer in Minneapolis kept his knee on the prone man’s neck for more than eight minutes sparked national protests; Daunte Wright, who was shot by a police officer who mistook her gun for her Taser during a traffic stop outside Minneapolis in 2021; Alton Sterling, who was shot by the police in Baton Rouge, La., in 2016; and others dating back decades, including the 1997 death of William J. Whitfield, an unarmed man fatally shot on Christmas Day in Brooklyn.

Mr. Nichols died on Jan. 10, three days after a traffic stop that turned into a brutal beating at the hands of Memphis police officers who were part of a specialized unit formed to help halt a surge of violence in the city.

In response to his death, police officials announced on Saturday that the unit had been disbanded. Jim Strickland, the mayor of Memphis, has also called for an extensive review of the Police Department. Two other police officers who were on the scene have been suspended pending the results of an investigation into their actions, as have two deputies from the Shelby County Sheriff’s Department. Two medics and a lieutenant from the Memphis Fire Department who responded to the scene have also been fired, officials said.

Video from the officers’ body cameras and a stationary surveillance camera that was released last week showed the assault and Mr. Nichols begging for his life. The encounter began as officers approached his vehicle — they claimed he had been driving erratically, although the city’s police chief has said no evidence of that has emerged — with guns drawn and pulled him from his car. The officers shouted often contradictory orders before using pepper spray on Mr. Nichols, who ran off.

But officers soon caught up with Mr. Nichols and severely beat him, with one officer delivering a series of blows to Mr. Nichols’s head while two other officers held his hands behind his back.

Mr. Nichols called out for his mother during the assault, which took place not far from her home.

Before the stop, his mother said, he had been on his way home from Shelby Farms, a sprawling public park just outside Memphis. He went there often to photograph the sunset. His photographs will be shown during the funeral.

“We get so zeroed in on how he died, we don’t get a chance to recognize that he lived before that moment,” Pastor Turner said.