The Department of Justice announced yesterday that there will be no federal charges filed against George Zimmerman in the 2012 shooting death of Trayvon Martin.

Zimmerman has maintained that he acted in self-defense when he shot the 17-year-old Martin during a confrontation inside a gated community in Sanford, Florida, just outside Orlando. Martin, who was black, was unarmed when he was killed. Zimmerman identifies himself as Hispanic.

Once Zimmerman was acquitted of second-degree murder by a state jury in July 2013, Martin's family turned to the federal investigation in final hopes that he would be held accountable for the shooting.

The DOJ investigation focused on whether Zimmerman intentionally deprived Martin of his civil rights, according to the federal hate crime laws. AP reports that "Federal investigators, who independently conducted dozens of interviews, ultimately determined there was insufficient evidence to prove Zimmerman killed the teenager on account of his race."

"Our decision not to pursue federal charges does not condone the shooting that resulted in the death of Trayvon Martin and is based solely on the high legal standard applicable to these cases," Vanita Gupta, the Justice Department's top civil rights lawyer, said in a statement announcing the decision.

Federal investigators said they examined the case under multiple civil-rights provisions, including ones that make it illegal to use force against someone based on their race and another that criminalizes race-based interference with a person's federally protected housing rights. They said they conducted roughly 75 witness interviews, examined police reports and reviewed all of the evidence gathered during the state prosecution.

Black leaders in Sanford, Florida said they were not surprised. "I was expecting this to happen," said Turner Clayton, a former local leader of the NAACP.