The US city of Memphis is preparing for the release of police video showing the beating of a black man whose death has prompted murder charges against five officers.
Amid outrage at the country's latest instance of police brutality, family members of Tyre Nichols pleaded for any protests to remain peaceful.
The officers, all of whom are black, were charged on Thursday with murder and other crimes in the killing of Mr Nichols, a motorist who died three days after a confrontation with the officers during a traffic stop on January 7.
Shelby County district attorney Steve Mulroy told a news conference that although the officers played different roles in the killing, “they are all responsible”.
Mr Nichols's family members and their lawyers said the footage shows officers savagely beating the 29-year-old FedEx worker for three minutes in an assault 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 on 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 on Friday evening, Mr Mulroy said, noting that local and state investigators wanted to complete as many interviews as possible before releasing it. Mr Nichols's family members viewed the footage on Monday.
Ms Davis said she and other local officials decided it would be best to release the video later on Friday after school has ended and people are home from work, given that protests are expected.
City schools cancelled all after-class activities and the Memphis power company's community offices and the University of Memphis also closed.
Mr Nichols's mother, RowVaughn Wells, said her family is “grief-stricken” and 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 on Thursday. “If you guys are here for me and Tyre, then you will protest peacefully.”
Ms Davis said: “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.
“None of this is a calling card for inciting violence or destruction on our community or against our citizens.”
On Thursday night, several dozen supporters joined Rodney and RowVaughn Wells for a peaceful candlelight vigil and prayer service at a Memphis skate park. Mr Nichols, who had a four-year-old son, was a keen 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.
Earlier on Thursday, Mr Nichols's stepfather, Rodney Wells, said 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, adding that he was “ecstatic” about how quickly the officers were fired and charged.
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.
The officers face charges of second-degree murder, aggravated assault, aggravated kidnapping, official misconduct and official oppression.
Four of the five had posted bond by Friday morning and had been released from custody, according to court and jail records.
Second-degree murder is punishable by 15 to 60 years in prison under Tennessee law.
Lawyers for Mr Nichols's family, Ben Crump and Antonio Romanucci, issued a statement saying he “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”.
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,” he added.
Ms 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 specialised units.
Mr Crump said the video showed Mr Nichols was pepper-sprayed, shocked 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 he was stopped for reckless driving and at some point fled from the scene.
Relatives accuse the police of causing him to have a heart attack and kidney failure. Authorities have only said he experienced a medical emergency.