Footage from a traffic stop in which five ex-Memphis police officers have been charged with murder shows them taking turns kicking and punching a motorist who screams for his mother.
In the videos from the arrest on January 7, officers can be seen beating Tyre Nichols, 29, for about three minutes.
Protests are taking place in Memphis and other cities across the United States, including New York.
Mr Nichols’ family’s lawyers compared the assault to the 1991 police beating of Los Angeles motorist Rodney King.
“Like so many, I was outraged and deeply pained to see the horrific video of the beating that resulted in Tyre Nichols’ death,” said US President Joe Biden, who has called for peaceful protests.
Mr Nichols was initially stopped by police on suspicion of reckless driving, which has not been proven. He died three days later, on January 10, in the hospital.
On Friday, the Memphis Police Department released four graphic videos depicting the traffic stop and its violent aftermath, totaling more than an hour of footage.
The first video shows officers dragging Mr Nichols out of his car and ordering him to get on the ground.
“I did nothing!” he exclaims. Officers order him to lie down flat.
“Get on the [expletive] ground!” one officer yells, while another says, “Tase him!”
“Put your hands behind your back before I break your [expletive]!” yells an officer.
“You guys are doing a great job right now,” Mr Nichols tells the officers. “All I want to do is get home.”
Within seconds, one of the officers fires a Taser at Mr Nichols, who leaps to his feet and flees.
A different video, captured by a CCTV camera mounted on a utility pole, shows officers beating Mr Nichols after apprehending him in a residential area.
Two officers are seen holding Mr Nichols down while others kick, punch, and strike him with an expandable baton.
They drag him across the ground, propped up against a squad car. More than 20 minutes pass before an ambulance arrives.