President Joe Biden said he was "outraged" and "deeply pained" after watching a violent encounter between Tyre Nichols, a 29-year-old Black man, and the five police officers charged with murder in his beating death after a traffic stop earlier this month.
"Like so many, I was outraged and deeply pained to see the horrific video of the beating that resulted in Tyre Nichols' death," Biden said in a statement.
He added the Nichols' families deserves a swift, full and transparent investigation.
The statement follows the release of a video showing five Memphis officers beating a black man, one day after they were charged with murder in the death of Tyre Nichols.
The footage shows Mr Nichols being held down, struck by the black officers and screaming for his mother as the police savagely beat the 29-year-old FedEx worker for three minutes.
The Nichols family legal team has likened the assault to the infamous 1991 police beating of Los Angeles motorist Rodney King.
Cities across the country braced for large demonstrations, with Mr Nichols’ relatives urging supporters to protest peacefully.
“This young man, by definition of the law in this state, was terrorised. Not by one, not by two, but by five officers who we now know… acted in concert with each other,” said attorney Antonio Romanucci, who represents Mr Nichols’ family.
The officers “acted together… to inflict harm, terrorism, oppression of liberty, oppression of constitutional rights, which led to murder,” Mr Romanucci said.
Memphis Police Director Cerelyn Davis described the officers’ actions as “heinous, reckless and inhumane”, and said that her department has been unable to substantiate the reckless driving allegation that prompted the stop.
Nichols' family and Biden appealed for calm in Memphis, a city of 628,000 where nearly 65% of residents are Black. Biden spoke with RowVaughn Wells and Rodney Wells, Nichols' stepfather, on Friday to express condolences, the White House said.
Nichols' death marked the latest high-profile instance of police officers accused of using excessive force in the deaths of Black people and other minorities in recent years.
Protests under the banner of the "Black Lives Matter" movement against racial injustice erupted globally following the May 2020 murder of Floyd, a Black man who died after a white Minneapolis police officer knelt on his neck for more than nine minutes.
Antonio Romanucci, another lawyer for Nichols' family, told National Public Radio on Friday that Nichols was a strong supporter of Black Lives Matter and "basically died for his own cause."
U.S. Attorney General Merrick Garland on Friday announced a federal civil rights investigation into Nichols' death.
Records show former officers Justin Smith, Desmond Mills Jr., Emmitt Martin III, Demetrius Haley and Tadarrius Bean were released on bond after they were booked into the Shelby County Jail on Thursday morning.
Defence attorney Blake Ballin, who represents Mills, said he and his client would review the videos "together at the appropriate time." He has said Mills will plead not guilty, as has a lawyer for Martin. Attorneys for Smith, Bean and Haley could not be reached.