The Rev. Al Sharpton urged marchers to remain nonviolent or go home Saturday ahead of a rally seeking justice in the death of an unarmed black man placed in a chokehold by a white police officer.
Sharpton spoke at the Mt. Sinai United Christian Church on Staten Island, telling about 100 people that violence was unacceptable at the rally.
He also repeated his call for a federal takeover of the criminal probe into the death of Eric Garner, who was put in a chokehold after officers with the New York Police Department stopped him for selling loose cigarettes.
An hour before the scheduled start of the rally, several thousand people had already gathered at the intersection where Garner died. Activists want criminal charges brought against the officers involved.
Many carried signs. Some said: "Police the NYPD" or "RIP Eric Garner." But the most popular signs were "Hands Up, Don't Shoot," which emerged during protests in Missouri over the police killing of Michael Brown, and "I can't breathe," Garner's last words, heard on a widely circulated video of the death.
The march comes five weeks after the death of Garner, a 43-year-old asthmatic father of six.
At the church, Garner's widow, Esaw, urged the crowd to march in peace toward justice.
Esaw Garner said she is too afraid to let her sons go outside and asked the rally to "get justice" for her husband.
The rally was to begin on the block where Garner died and end outside the office of Staten Island District Attorney Daniel Donovan, who this week sent the case to a grand jury.
Sharpton has repeatedly called Garner's death — and the shooting death of 18-year-old Brown by police in Ferguson, Missouri — a "defining moment" for policing nationwide. Members of both Garner's and Brown's family were expected at the "We Will Not Go Back" march.
Garner, an asthmatic father of six, was unarmed when he was stopped July 17. Garner was placed in a chokehold — an illegal police tactic — and could be heard screaming "I can't breathe!" as he was forced to the ground.
Soon after, he was declared dead. The city medical examiner ruled the death a homicide and two NYPD officers have been reassigned during the investigation.
So far, the U.S. Justice Department has signaled it likely will wait for the local probe to conclude before deciding whether to launch a formal civil rights investigation.
Saturday's half-mile-long route winds through a heavily minority neighborhood, one of several in the nation's largest city where residents have said they feel unfairly targeted by police for suspicion of crime and enforcement of low-level offenses.