'He took a life.' Trayvon Martin's mother disappointed by lack of charges in son's shooting death

An image of Trayvon Martin and a bullet shell keychain hanging from a protester's lanyard are seen during a demonstration in reaction to the acquittal of neighborhood watch volunteer George Zimmerman in Los Angeles on Monday, July 15, 2013. (AP / Jae C. Hong)

MIAMI -- The mother of Trayvon Martin says she's disappointed that federal prosecutors decided not to charge a neighbourhood watch volunteer with a hate crime for killing her son three years ago.

The case sparked a national conversation about race, bias and crime in part because George Zimmerman, who identifies himself as Hispanic, was not immediately arrested after shooting Martin, who was black and unarmed.

Speaking with The Associated Press on Wednesday before the third anniversary of her 17-year-old son's death, Sybrina Fulton says she still believes Zimmerman got away with murder.

"He took a life, carelessly and recklessly, and he shouldn't deserve to have his entire life walking around on the street free. I just believe that he should be held accountable for what he's done," Fulton said.

Zimmerman claimed he shot the unarmed teenager in self-defence after confronting Martin while volunteering for his neighbourhood watch group. A jury acquitted him of second-degree murder the next year.

The U.S. Justice Department announced Tuesday that it found insufficient evidence to establish that Zimmerman wilfully deprived Martin of his civil rights or killed him because of his race.

"The Justice Department is the top of the line here," Fulton said. "But what they found just wasn't enough."

Zimmerman's attorney, Don West, said his client is relieved the case is closed, according to his attorney.

"This cloud he was under has been lifted," West told the AP, adding that he finds it misleading to suggest that charges weren't filed only because the legal standard for federal hate crime is so tough to meet.

"There simply was never any compelling evidence that this was a federal hate crime. Race played no role in it whatsoever," West said.

The February 2012 confrontation began after Zimmerman spotted Martin walking through the neighbourhood, returning to his father's home after buying candy and a soft drink at a convenience store.

Zimmerman called police to report a suspicious person, and got out of his car to follow Martin despite being warned by the dispatcher to stop. Zimmerman did not testify at his trial, but he told investigators he feared for his life as Martin straddled him and punched him during the ensuing fight.

Wearing a T-shirt bearing a black-and-white image of her son in a hoodie, Fulton said she still longs for Zimmerman to be held responsible.

Fulton now channels her grief into work with The Trayvon Martin Foundation, which reaches out to other families who have lost children to violence, awards scholarships and collects school supplies for poor students.

She's also watching to see how the Justice Department handles other high-profile killings of unarmed African-Americans. Decisions are pending on whether to charge police in New York and Ferguson, Missouri, with depriving the victims of their civil rights by using excessive force in the course of duty.

"What we want is accountability, we want somebody to be arrested, we want somebody to go to jail, of course," Fulton said. "But ... we have grand juries and special grand juries; they're making a decision to not even arrest a person."