“That these five officers are being held criminally accountable for their deadly and brutal actions gives us hope as we continue to push for justice for Tyre,” the family’s lawyer, Ben Crump, said in a statement. He added, “This tragedy meets the absolute definition of a needless and unnecessary death.”

Mr. Nichols worked the second shift at a FedEx facility, the shipping company that is a major employer and corporate presence in Memphis. Every evening, around 7 p.m., he would return to his mother’s house for his “lunch” break, according to his family. He had worked there for roughly nine months.

He had a 4-year-old son. He went to the same Starbucks most mornings around 8:30 a.m., his mother said. He often went to Shelby Farms, a sprawling public park just outside Memphis. He photographed sunsets and skateboarded, a passion that he had had since he was 6 — one his stepfather thought he was too old for. “You’ve got to put that skateboard down,” Mr. Wells remembered telling Mr. Nichols not long before he died. “You’ve got a full-time job now.”

His mother said that Mr. Nichols had her name tattooed on his arm. “That made me proud,” she said. “Most kids don’t put their mom’s name. My son was a beautiful soul.”

According to the family’s lawyers, Mr. Nichols told the officers during the Jan. 7 events that he just wanted to go home, and in what they believed were his final words, he called out for his mother. Her home was about 100 yards from where he was beaten, the lawyers said.

City officials have promised transparency and Mr. Mulroy, the Shelby County district attorney, said the footage of the beating would be released to the public sometime after 6 p.m. on Friday. The footage will amount to nearly an hour from police body cameras and stationary cameras, with limited redactions, such as blurring out the faces of people who are not city employees.

“People will be able to see the entire incident from beginning to end,” Mr. Mulroy said.

Officials anticipate an angry public reaction to the footage, which has been repeatedly called brutal, and Memphis is bracing.