Reverend Al Sharpton has declared that "Stephon Clark has woken up the nation" as hundreds of mourners gathered to honour and chant the name of the 22-year-old, who was shot by police officers in his grandparents’ backyard.

Sacramento police officers responding to reports of vehicle break-ins opened fire when they encountered Mr Clark, discharging their weapons 20 times as one officer shouted “Gun”! Searching the scene in the aftermath, they found only a mobile phone.

The shooting has ignited waves of protests in Sacramento and fanned a national outcry about another black man being killed by police officers. Demonstrators in Sacramento have disrupted a city council meeting before testifying for hours about inequality and prejudice, stymied freeway traffic during rush hour and twice prevented fans from entering the basketball arena where the NBA's Sacramento Kings plays.

Just as protesters have regularly massed in the days since Mr Clark's death to condemn his killing, his funeral attracted an overflow crowd that saw people waiting to enter the packed church well after the service began. Mr Sharpton, a prominent civil rights activist, travelled to Sacramento to deliver the eulogy. Speakers urged attendees to make Mr Clark's death an impetus for activism against police violence.

“They’ve been killing young black men all over the country, and we’re here to say we’re going to stand with Stephon Clark,” Mr Sharpton said of the shooting last week.

“We will never let you forget the name of Stephon Clark until we get justice,” he added, echoing calls for the officers involved to face charges by saying calling for “the prosecutor to bring justice in the name of Stephon Clark”.

“This is not a Sacramento fight anymore. This is a national fight. Stephon has woken up the nation”, Mr Sharpton said. “We’re going to make Donald Trump and the whole world deal with the issue of police misconduct”.

Mr Clark’s brother Stevante, who earlier in the week strode into a city council meeting and dramatically confronted Sacramento’s mayor, interrupted a speech to take the stage and lead a call-and-response chant of “I am - Stephon” that Mr Sharpton later took up.

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“The Clark family will never die”, Stevante said, before calling for measures like founding a library in his brother’s name.

A flower arrangement near the casket where Stephon lay bore the words “Rest in Power”, a phrase invoked by activists who have urged police reforms in response to Mr Clark's death. Speakers offered up prayers for young black men across the nation.

After Mr Clark's funeral protesters gathered outside the office of Sacramento district attorney Anne Marie Schubert and, as they have in days of demonstrations there, urged the prosecutor to charge the officers who killed Mr Clark.

Asked about Donald Trump’s position on the shooting the day before the funeral, White House Press Secretary Sarah Huckabee Sanders called Stephon’s death a “terrible incident” but repeatedly said it was not a matter for the federal government. Speakers at Stephon’s funeral lambasted that statement.

Stephon Clark's brother disrupts Sacramento City Council meeting after police shooting

“Even though the president don’t think this is national, the media does”, said Alice Huffman, president of the California chapter of the National Association for the Advancement of Colored People.

With anger surging through the community and driving mass protests in the days since Stephon was killed, elected officials and institutions have been scrambling to respond.

State attorney general Xavier Becerra announced his office would oversee the investigation of the shooting. Having an outside agency monitor the probe is intended to ensure thoroughness and impartiality, and Mr Becerra noted that his office has the authority to recommend prosecution of the officers involved.