MEMPHIS, Tenn. — The city of Memphis and the nation on Friday braced for the release of a police video depicting five officers viciously beating Tyre Nichols, a Black man whose death prompted murder charges against them and outrage at the country’s latest instance of police brutality.

The officers were charged Thursday with murder and other crimes in the killing of Nichols, a motorist who died three days after a confrontation with the officers during a traffic stop on Jan. 7.

Shelby County District Attorney Steve Mulroy told a news conference that although the officers each played different roles in the killing, “they are all responsible.”

The officers, who are all Black, each face charges of second-degree murder, aggravated assault, aggravated kidnapping, official misconduct and official oppression.

Nichols' family members and their lawyers said the footage shows officers savagely beating the 29-year-old FedEx worker for three minutes in an assault that the legal team likened to the infamous 1991 police beating of Los Angeles motorist Rodney King.

Memphis Police Director Cerelyn Davis described the officers' actions as “heinous, reckless and inhumane,” and said Friday that her department has been unable to substantiate the reckless driving allegation that prompted the stop.

“As far as I know today, I do believe that the stop itself was very questionable,” she told Good Morning America.

Video of the traffic stop will be released to the public sometime Friday evening, Mulroy said, noting that local and state investigators wanted to complete as many interviews as possible before releasing it. Nichols' family members viewed the footage on Monday.

Davis told GMA that she and other local officials decided it would be best to release the video later in the day Friday after schools have let out and people are home from work, given that protests are expected to erupt.

As a precaution, Memphis area schools canceled all after-class activities and postponed a school event scheduled for Saturday morning. Other early closures include the Memphis power company's community offices and the University of Memphis.

Nichols' mother, RowVaughn Wells, who said her family is “grief-stricken,” warned supporters of the “horrific” nature of the video but pleaded for peaceful protests.

“I don’t want us burning up our city, tearing up the streets, because that’s not what my son stood for,” she said Thursday. “If you guys are here for me and Tyre, then you will protest peacefully.”

Davis also urged calm after the video’s release.

“I expect our citizens to exercise their First Amendment right to protest, to demand actions and results, but we need to ensure our community is safe in this process,” she said Thursday. “None of this is a calling card for inciting violence or destruction on our community or against our citizens.”

Nichols’ stepfather, Rodney Wells, told The Associated Press by phone that he and RowVaughn Wells discussed the second-degree murder charges and are “fine with it.” They had sought first-degree murder charges.

“There’s other charges, so I’m all right with that,” he said.

Rodney and RowVaughn Wells were joined by several dozen supporters on a cold Thursday night for a candlelight vigil and prayer service at a Memphis skate park. Nichols, who had a 4-year-old son, was an avid skateboarder.

Activists and clergy led the group in prayer and a drummer played a steady rhythm to lead into the spoken part of the vigil. Afterward, skaters rode their boards as the Wellses watched.

Court records showed that all five former officers — Tadarrius Bean, Demetrius Haley, Desmond Mills Jr., Emmitt Martin III and Justin Smith — were taken into custody.

Martin's lawyer, William Massey, confirmed that his client had turned himself in. He and Mills' lawyer, Blake Ballin, said their clients would plead not guilty. Lawyers for Smith, Bean and Haley could not be reached.

“No one out there that night intended for Tyre Nichols to die,” Massey said.

Both lawyers said they had not seen the video.

“We are in the dark about many things, just like the general public is,” Ballin said.

Second-degree murder is punishable by 15 to 60 years in prison under Tennessee law.

The attorneys for Nichols' family, Ben Crump and Antonio Romanucci, issued a statement saying that Nichols "lost his life in a particularly disgusting manner that points to the desperate need for change and reform to ensure this violence stops occurring during low-threat procedures, like in this case, a traffic stop.”

At the White House, President Joe Biden said the Nichols family and the city of Memphis deserve “a swift, full and transparent investigation.”

“Public trust is the foundation of public safety, and there are still too many places in America today where the bonds of trust are frayed or broken,” Biden said in a statement.

Davis said other officers are still being investigated for violating department policy. In addition, she said “a complete and independent review” will be conducted of the department’s specialized units, without providing further details.

Two fire department workers were also removed from duty over the Nichols’ arrest.

As state and federal investigations continue, Davis promised the police department’s “full and complete cooperation” to determine what contributed to Nichols’ Jan. 10 death.

Crump said the video showed that Nichols was shocked, pepper-sprayed and restrained when he was pulled over near his home. He was returning home from a suburban park where he had taken photos of the sunset.

Police have said Nichols was stopped for reckless driving and at some point fled from the scene.

Relatives have accused the police of causing Nichols to have a heart attack and kidney failure. Authorities have only said Nichols experienced a medical emergency.

One of the officers, Haley, was accused previously of using excessive force. He was named as a defendant in a 2016 federal civil rights lawsuit while employed by the Shelby County Division of Corrections.

The claims were ultimately dismissed after a judge ruled that the plaintiff had failed to file a grievance against the officers within 30 days of the incident.