Mr Nichols, 29, was fatally beaten by five police officers in January.

Speaking to US media, Ben Crump urged President Joe Biden to use Mr Nichols's death to gain support for the George Floyd Justice in Policing Act.

And he said Mr Nichols's mother was coping with her son's loss by hoping that his death could lead to change.

"She believes in her heart Tyre was sent here for an assignment and that there is going to be greater good that comes from this tragedy," Mr Crump said.

The George Floyd Justice in Policing Act was introduced in 2021 after Mr Floyd was killed by a white police officer kneeling on his neck for more than nine minutes. His death sparked international protests.

The bill would see a federal ban on the use of chokeholds by police and make it easier to bring charges against offending officers.

Lawmakers in the House of Representatives - which was then controlled by the Democratic Party - passed the bill in March 2021, but it was later held up by opposition in the Senate.

"Shame on us if we don't use his tragic death to finally get the George Floyd Justice in Policing Act passed," Mr Crump told CNN. The lawyer said if the law did not change, deaths at the hands of police would continue.

Derrick Johnson, the president of the NAACP civil rights group - also called on legislators to take action.

"By failing to write a piece of legislation, you're writing another obituary," Mr Johnson said in a statement. "We can name all the victims of police violence, but we can't name a single law you have passed to address it."

But the Republican House of Representatives Judiciary chair Jim Jordan warned politicians to not rush legislation.

"These five individuals did not have any respect for life... I don't know if there's anything you can do to stop the kind of evil we saw in that video," he told NBC's Meet the Press programme.

A childhood friend of Mr Nichols told the BBC his legacy would be preserved through legal reform. Angelina Paxton said he "always wanted to change the world".

Ms Paxton said Mr Nichols was "very passionate about Black Lives Matter".

"He always wanted to make a difference," she said. "If it gives anyone any comfort out of all those pain that we're all going through right now, just know that I can guarantee you he's up there right now smiling, because he finally did what he always wanted to do."

On Saturday, the Memphis Police Department disbanded the so-called Scorpion special unit of which the police officers now charged with murder were members.

The unit was a 50-person team that was tasked with bringing down crime levels - particularly car thefts and gang-related offences.

Scorpion stood for "Street Crimes Operations to Restore Peace in Our Neighborhoods".

The five officers - Tadarrius Bean, Demetrius Haley, Desmond Mills Jr, Emmitt Martin III and Justin Smith - were fired from the Memphis police force last week.

Four of the five posted bail and were released from custody by Friday morning, according to jail records.

Lawyers for Mr Martin and Mr Mills have said their clients will plead not guilty.

In an interview with BBC News on Friday, Memphis Police Chief CJ Davis said the Scorpion unit was created to be "more responsive" and "more proactive" to gun violence in the city. But she acknowledged that the officers who brutally beat Tyre Nichols "decided to go off the rails".

"We are doing an individual evaluation of all units," she said. "This is a necessary step. We want to be fully transparent to the community."

Shelby County Sheriff Floyd Bonner Jr said two deputy sheriffs who "appeared on the scene following" the confrontation have also been suspending pending an internal investigation.