Martin's family and supporters maintain that Zimmerman racially profiled Martin and decided to follow him, leading to the fatal fight. Supporters of the Justice Department filing civil rights charges say additional evidence could exist in the federal investigation that didn't come up in the state prosecution of Zimmerman, possibly even unknown witnesses.
Several civil rights groups, including the NAACP, are demanding that the Justice Department bring federal charges against Zimmerman, and there have been numerous protests around the country about the outcome of the Florida trial. Beyond the exact language of the law itself, the federal probe must navigate between sensitive racial and political issues that arose when Zimmerman initially wasn't charged in Martin's killing.
Barbara Arnwine, president and executive director of the Lawyers Committee for Civil Rights Under Law, called the verdict "a travesty and miscarriage of justice" and urged the Justice Department to bring criminal civil rights charges against Zimmerman.
Zimmerman could get life in prison if charged and convicted under federal hate crime laws.
Several former prosecutors said they'd be surprised if the department were to charge Zimmerman under civil rights laws.
"I think it would be a very steep, if not insurmountable, hill to climb and would be shocked to see any further DOJ involvement," said Jeffrey Sloman, former U.S attorney in Miami.
Sundby said the legal system does not always provide an outcome that satisfies people who believe Martin's killing was unjustifiable and morally wrong.
"That's frustrating as a lawyer to say, but sometimes the legal system -- even if there's a sense that an injustice was done -- it doesn't have an answer to that injustice," he said.