Chokehold death going to grand jury

People participate in a demonstration against the death of Eric Garner after he was taken into police custody in Staten Island. Joel Graham photographed the demonstration, and captured this image of Garner's friends and family rallying alongside the Rev. Al Sharpton.

Crowds of people rally in Upper Manhattan on Saturday.

While photographing the demonstration, Graham says, he saw a New York Police Department presence at the event. "The NYPD appeared genuinely sympathetic to the marchers, giving everyone wide latitude to voice their frustrations," he said.

Garner's mother, Gwen Carr, speaks at the demonstration.

Garner's family, friends and people from the Staten Island community gathered to demand a full investigation into the incident.

• Eric Garner died on July 17 after police stopped him for allegedly selling cigarettes illegally


• An officer seen in a video placing Garner in a chokehold has been stripped of his badge


• Prosecutors say the grand jury will begin hearing evidence next month

New York (CNN) -- Evidence in the investigation of the controversial chokehold death of Staten Island man Eric Garner will be presented to a grand jury, prosecutors announced Tuesday.

The grand jury will convene in September, Richmond County District Attorney Daniel M. Donovan said.

Garner, 43, died on July 17 after police confronted him on Staten Island for allegedly selling cigarettes illegally. During the encounter, a video shows a police officer grabbing the 350-pound man in a chokehold and pulling him onto a sidewalk.

The New York City Police Department prohibits the chokehold tactic.

"After a careful review of the recent findings of the Medical Examiner regarding the cause and manner of Mr. Garner's death, I have determined that it is appropriate to present evidence regarding the circumstances of his death to a Richmond County Grand Jury," Donovan said in a statement.

Man dies after NYPD chokehold

Prosecutors provided no additional information about the exact date that the grand jury will convene, what witnesses will testify, what criminal charges will be considered or whom those charges could be levied against.

The New York City medical examiner ruled Garner's death a homicide. The cause of death was "compression of neck (choke hold), compression of chest and prone positioning during physical restraint by police."

The controversial death has sparked several anti-police demonstrations throughout New York City in the month since it happened. Demonstrators have called the police response during his arrest excessive and criminal.

Opinion: What led to chokehold death?

In his statement, Donovan said that prosecutors are committed to conducting "a fair, thorough and responsible investigation into Mr. Garner's death," adding that "no person is above the law, nor beneath its protection."

The video that surfaced after his death shows Garner lying on the ground motionless after he was taken down by a group of officers. Garner, an asthmatic, was later declared dead at a nearby hospital.

After the incident, New York City Police Commissioner William Bratton ordered an extensive review of the New York Police Department's training procedures.

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 NYPD said. A second police officer was placed on desk duty.

Two EMTs and two paramedics also were suspended without pay, said Erika Hellstrom, vice president of development at Richmond University Medical Center.

Garner, a grandfather with six children, had a lengthy criminal history, including more than 30 arrests, and had been arrested for selling untaxed cigarettes in May, police said.

Man who filmed cop's fatal chokehold arrested on gun charges

CNN's Ray Sanchez contributed to this report.