The sanctuary on the Bayside of South Sacramento church, called the BOSS Church, was crowded with people, many of whom were sitting outside when 22-year-old Clark's funeral took place.
"We will never forget the name of Stephon Clark until we get justice," Sharpton told the mourners.
Sharpton spoke into the microphone while being hugged by Clark's brother Stevante, who had just interrupted the service with an emotional request never to forget his brother.
On March 18, police shot dead Stephon Clark in his grandmother's garden, causing protests. The police said they thought Clark had a gun, but only his cell phone was found on the scene.
In his eulogy, Sharpton disagreed with the White House spokeswoman, Sarah Sanders, who called Clark's shots a "local affair" left to local authorities
"No, that's not a local affair – they've got it all together Land killed young black men, "said Sharpton. "It's time for preachers to come from the pulpit, it's time for politicians to come out of the office, it's time for us to stop this madness."
Sharpton pointed out that protests against Clark's death have * 19659002] "They are not violent, they demand that you stop being violent against them," Sharpton said. "They do not try to hurt anyone, they try to express their pain."
The shooting took place after the Sacramento officers responded to a report that a man had broken a car window and hid behind a house. The police said they had pursued a man – later called Clark – who hopped a fence into his grandmother's property.
The officers, one of whom is black, were detained during the investigation. Clark's family has denied the police account.
Protesters are gathering in front of the District Attorney for the District of Sacramento this week, holding their cell phones in relation to the cell phone found near Clark's body.
"Cell phone does not shoot," They sang. "
They plotted another protest on Thursday at the same location.
Protesters talked about other shootings of African-Americans and their frustration with a legal system from which they say that it has failed to prosecute or convict officials.
Sacramento police chief Daniel Hahn announced this week that California Attorney General Xavier Becerra will conduct an independent investigation into the incident.
The boss said he had the supervision of prosecutors required, although he had confidence in his detectives to be impartial.
The police released 72 hours after the incident footage of Clark's shooting, and Hahn said that The authorities are still collecting facts and conducting a thorough investigation.
In the footage, someone may be heard the officers mute their body cameras. The comment comes about seven minutes after Clark was shot several times – and it did not do well with the community.
Hahn told CNN he did not know why the cameras were muffled. Officers are allowed to do this in certain situations, for example when talking to a confidential informant.
"The bigger question, beyond this particular case, is if we should allow people to mute their microphones at all, or in those circumstances," he said Tuesday. "We looked at it before this incident happened, but I think this incident is a perfect example of why that's a problem."
"Every time this camera mutes, suspicion arises in this case."
The Sacramento Kings prepared for further protests before their game on Thursday against the Indiana Pacers at 7 pm (10 pm ET)
The team encouraged fans to arrive early and get their tickets ready.
Last week, Kings owner Vivek Ranadivé conveyed sympathy to the Clark family. He was accompanied by the players, coaches and team managers of the team.
"We are aware that it is not just business as usual, and we will work really hard to bring everyone together to enhance the world's own community, and we will work really hard to prevent that such a tragedy will happen again, "he said.
During Sunday's game, the Kings and Boston wore Celtic's warm-up shirts saying "Accountability. We Are One" on the front and "# StéphonClark" on the back.
Dan Simon and Madison of CNN Park contributed to this report.