Anger is still simmering over Nichols' death on January 10, three days after he was beaten and kicked in a traffic stop by five Black police officers -- rekindling a national debate about brutality in law enforcement.
Calling out the officers over the deadly "act of violence," Harris urged Congress to pass a stalled reform bill named for George Floyd, whose murder by police in 2020 ignited waves of unrest across the country and beyond.
Speaking though tears, Nichols' mother RowVaughn Wells joined Harris in calling on lawmakers to act -- flanked by the veteran civil rights leader Al Sharpton who delivered the eulogy for her son.
"We need to take some action," Wells said. "Because if we don't, the next child that dies -- that blood is going to be on their hands."
During the ceremony, Nichols was remembered as "a beautiful soul, a son, a father, a brother, a friend, a human being, gone too soon," in the words of Reverend J. Lawrence Turner.
Mourners were shown pictures shot by the young man, a keen photographer, as well as clips of him skateboarding -- another passion.
"All I want is my baby brother back," said Keyana Dixon, his older sister, who noted that even as he was being beaten by police her brother remained polite asking them to "Please stop."
Another relative read a poem inspired by the excruciating footage of his fatal encounter with police, titled "I'm Just Trying To Go Home."
In a sign of the far-reaching resonance of Nichols' death, Harris was joined at the funeral by the director Spike Lee, and by relatives of other Black victims of police violence, including George Floyd's brother Philonise Floyd.
Also present was Tamika Palmer, the mother of Breonna Taylor, who was killed in a botched raid on her Kentucky home in 2020.
Like Floyd, Taylor has since become one of the icons of the Black Lives Matter movement seeking police reform and racial justice.
- 'Thugs' -
Nichols was arrested by members of a special police unit called Scorpion in Memphis on January 7 for what police said was a traffic violation.
He was beaten viciously, as recorded in body camera and security camera footage that triggered national outrage when it was made public last week.
The five officers involved have been fired and are facing murder charges. Two others along with three firefighters have been suspended as the investigation continues.
In his eulogy, Sharpton said the officers had betrayed the spirit of the movement led by Martin Luther King, who was shot dead in a racist attack in Memphis in 1968.
African Americans would never have been hired by Memphis police without the campaign led by King, said Sharpton.
"People had to march and go to jail and some lost their lives to open the doors for you. And how dare you act like that sacrifice was for nothing?"
"You don't fight crime by becoming criminals yourself," he said. "You don't stand up to thugs in the street becoming thugs yourself."
Sharpton also argued that Nichols' race was a factor in how police treated him, saying the officers would not have subjected a white person to such a beating.
City data published by The New York Times showed that while Black residents make up two-thirds of the population of Memphis, since 2016 they had accounted for 86 percent of encounters in which police used force.
President Joe Biden had also reached out to Nichols' family ahead of the funeral, declaring himself "outraged and deeply pained" by his death.
Like Harris, the president has renewed calls for police reform -- which he is set to discuss at the White House on Thursday with members of the Congressional Black Caucus.
As Nichols' funeral took place, a new uproar was building over a bystander video from Los Angeles that appears to show the moments before police officers shot dead a double amputee, an African American, as he fled on his stumps.
The officers involved said they were responding to reports of an unprovoked stabbing carried out by a man in a wheelchair.
