Outrage over the killing of an unarmed Florida teenager grew nationwide Wednesday as at least 1,000 supporters of Trayvon Martin took to the streets of New York and a petition demanding the shooter's arrest amassed nearly 1 million signatures.

Members of Martin's family were among demonstrators in New York for a "Million Hoodie March," a reference to the attire the 17-year-old was wearing when he was shot.

"A black person in a hoodie isn't automatically suspicious," an online protest page says. "Let's put an end to racial profiling."

More than 900,000 people have signed a petition on Change.org demanding the arrest of the shooter, George Zimmerman.

Martin was fatally shot February 26 while walking to the house of his father's fiancee in Sanford, Florida, after a trip to a convenience store. Zimmerman, a neighborhood watch leader, said he shot the teen in self-defense.

Zimmerman has not been arrested or charged. A police report describes him as a white male; his family says he is Hispanic.

Demonstrators of all races crowded into New York's Union Square on Wednesday night, demanding justice. Many of them wore hoodies and carried Skittles, the candy Martin had bought on the night he was killed.

"I am Trayvon Martin!" the crowd chanted as they marched for about an hour, returning to Union Square. Others chanted, "I'm a suspicious person," a reference to the shooter's description of Martin to a 911 operator. A boy carried a sign that read, "Will I be next?"

"We will not go quietly into the night," Benjamin Crump, the Martin family's attorney, told the protesters. "We have to make sure we understand what happened so we can never let this tragedy happen again."

"No justice, no peace!" the crowd chanted.

"George Zimmerman took Trayvon's life for nothing," the teenager's father, Tracy Martin, told the demonstrators. "Our son did not deserve to die. There's nothing that we can say that will bring him back, but I'm here today to assure that justice is served and that no other parents have to go through this again."

"Our son is your son," Martin's mother, Sybrina Fulton, told the crowd. "This is not about a black-and-white thing. This is about a right-and-wrong thing. Justice for Trayvon!"

Earlier, she described her situation as "a nightmare" to Anderson Cooper on his talk show. "It's hard to sleep," she said about her son. "Everything reminds me of him, and the only thing that's fueling us to keep pressing on for justice is the fact that we know that justice will be served."

Tracy Martin said race played a role in the police investigation. "Had Trayvon been a white kid ... Zimmerman would have been arrested," he said.

On Wednesday night, the Sanford City Commissioners, passed by 3-2 a no-confidence vote in Sanford Police Chief Bill Lee. It was not immediately clear what impact, if any, that would have.

The vote came a day after Ben Jealous, head of the NAACP, demanded Lee's resignation, accusing him of having mishandled the case by not arresting Zimmerman.

The U.S. Justice Department has launched a civil rights investigation into the shooting.

The incident occurred when Zimmerman, who was patrolling the neighborhood, saw the teen walking home after buying candy and a drink at a convenience store.

Zimmerman called 911 and reported what he described as a suspicious person. Moments later, several neighbors called the emergency number to report a commotion outside.

Heated debate has erupted over whether Zimmerman used a racial slur during the 911 call, a recording of which was released this week.

"We didn't hear it. However, I am not sure what was said," Sgt. David Morgenstern of the Sanford Police Department said.

"I have listened to the tapes, and I have not heard them use a racial slur," concurred Sanford City Manager Norton Bonaparte.

A top CNN audio engineer enhanced the sound of the 911 call, and several members of CNN's editorial staff repeatedly reviewed the tape but could reach no consensus on whether Zimmerman used a racial slur.

Whether Zimmerman used such language prior to shooting Martin is key, according to CNN Senior Legal Analyst Jeffrey Toobin. "It's extremely, extremely significant because the federal government is not allowed to prosecute just your ordinary, everyday murder. Two people fighting on the street is not a federal crime. However, if one person shoots another based on racial hostility, racial animus, that does become a federal crime."

Toobin said that if "very shortly before" the shooting, "Zimmerman used this racial epithet to refer to the person he openly shot, that very much puts it within the FBI's and the Justice Department's ambit of a case that they could prosecute."