NEW YORK - Thousands of protesters rallied Saturday on a New York street where Eric Garner, an unarmed black man, died after a white police officer put him in a chokehold, sparking national outrage just weeks before Michael Brown was shot to death by a police officer in Ferguson, Missouri.
The two cases thrust into the forefront the issues of law enforcement's use of deadly or life-threatening force and police relations with the communities they are sworn to serve.
On Saturday, as former classmates at the Normandy High School football game in Ferguson held a moment of silence for Brown and the local NAACP led a march calling for justice, demonstrators gathered more than 900 miles away on the Staten Island street where Garner died.
The "We Will Not Go Back March" was led by the Rev. Al Sharpton's National Action Network, whose members also participated in demonstrations in Ferguson.
At times, the Missouri protests erupted into looting and clashes with law enforcement officers. Organizers said thousands participated in the New York march and rally -- during which no arrests were reported.
"I have seven grandsons," said a marcher who identified herself only as Diane and said Eric Garner was her friend and neighbor. "I don't want what happened to Eric and Michael Brown to happen to them."
The march started on the street where the 43-year-old, 350-pound Garner crumbled after being placed in a chokehold during a confrontation with the police for allegedly selling cigarettes illegally.
It proceeded to the office of the county district attorney, where a grand jury is to consider evidence in the death.
"We are here looking for justice," Staten Island resident Kim Jenkins said.
Demonstrators carried signs with messages such as "Justice for Eric Garner," "Black Lives Matter" and "Hold Killer Cops Accountable."
Speakers cited a litany of names of men and woman who died at the hands of police throughout the country. The marchers included members of New York labor unions and local politicians.
Kadiatou Diallo recalled the day her unarmed 22-year-old son Amadou who was killed in February 1999 in a hail of 41 bullets fired by four police officers in the Bronx. He was struck 19 times. Before the rally, she met relatives of Eric Garner, including his wife.
"It is not a black and white," Diallo told the crowd. "We are not against the police, the NYPD or the police nationwide. It is about wrong. ... We have to stop this. Too many tears. Too many victims."
Former New York Gov. David Paterson told demonstrators: "We will not stop until somebody goes to jail."
During his fatal police encounter, Garner raised both hands in the air and told the officers not to touch him. Seconds later, a video shows an officer behind him grab him in a chokehold and pull him to the sidewalk, rolling him onto his stomach.
"I can't breathe! I can't breathe!" Garner said repeatedly, his cries muffled into the pavement.
The cause of Garner's death was "compression of neck (chokehold), compression of chest and prone positioning during physical restraint by police," said Julie Bolcer, a spokeswoman for the medical examiner's office. The death was ruled a homicide.
Acute and chronic bronchial asthma, obesity and hypertensive cardiovascular disease were listed as contributing factors in a controversial death that fueled anti-police demonstrations and calls for a federal charges against the officer.
The video showed Garner lying on the ground motionless after he was taken down. An asthmatic and father of six, Garner was later declared dead at a nearby hospital.
Officer Daniel Pantaleo, who is seen on the video choking Garner, was put on modified assignment and stripped of his badge and gun amid the investigation, the New York Police Department said. A second police officer was placed on desk duty. The chokehold is prohibited by the NYPD.
Two EMTs and two paramedics also were suspended without pay, according to Erika Hellstrom, vice president of development at Richmond University Medical Center.
Police Commissioner William Bratton ordered an extensive review of the NYPD's training procedures after Garner's death.
The U.S. Justice Department has said it is monitoring the investigation. If local prosecutors decline to file criminal charges, the department could conduct an investigation into whether the victim's civil rights were violated.
CNN's Lawrence Crook III contributed to this report.