Thousands gathered in New York City on Wednesday for a "Million Hoodie March" to show their support for Florida teen Trayvon Martin, who was recently gunned down by a neighborhood watch vigilante.

"My heart is in pain," Martin's mother, Sybrina Fulton, told the crowd. "But to see the support of all of you really makes a difference."

Supporters wearing hooded sweatshirts similar to what Martin was wearing when he killed chanted "We are all Trayvon!" and "We want arrests!"

As head of neighborhood watch for The Retreat at Twin Lakes, George Zimmerman had called police in February to report 17-year-old Martin as a suspicious person, but by the time the officers arrived, the young man was already dead.

According to reports, police said Martin had been returning from a local store with Skittles and an iced tea.

Zimmerman claimed he had been forced to use his 9mm handgun shoot Martin in self-defense.

Tapes from 911 dispatchers later revealed that Zimmerman had been told not to pursue Martin. While the teen did not have a criminal record, Zimmerman had been charged in 2005 with “resisting arrest with violence and battery on an officer.” Those charges were later reduced to simple battery, and a plea deal allowed him to carry a concealed weapon.

A profile by The Miami Herald described Zimmerman as someone who was “fixated on crime and focused on young, black males.” He had called police at least 46 times since January 1, 2011.

Local authorities have made no arrests in the case, but the Justice Department has opened an investigation.

“We’re not going to stop until we get justice,” Martin's father, Tracy Martin, announced to the marchers on Wednesday. “My son did not deserve to die.”

Watch this video from WABC, broadcast March 21, 2012.