The Justice Department announced that it will not press charges against George Zimmerman. Officials cited there was insufficient evidence to believe Zimmerman had committed a hate crime when he shot and killed Trayvon Martin.

US Attorney General Eric Holder said that the DOJ's investigation did not find enough evidence to meet the "high standard for a federal hate crime prosecution." He did, however, stress the importance of exploring racial injustice in the judicial system.

"This young man's premature death necessitates that we continue the dialogue and be unafraid of confronting the issues and tensions his passing brought to the surface," Holder said in a statement. "We, as a nation, must take concrete steps to ensure that such incidents do not occur in the future."

© AP Photo / Martin Family Trayvon Martin

Zimmerman shot 17-year-old Martin in February of 2012 while acting as part of a neighborhood watch group. A confrontation ensued after Zimmerman approached the teenager, believing him to be behaving suspiciously. Martin had been returning home after buying skittles and a bottle of iced tea.

Zimmerman claimed he shot Martin in self-defense, and was acquitted of both manslaughter and murder charges by a Florida jury in 2013. Days after that decision, Holder said he considered Martin's death an "unnecessary shooting," according to the Associated Press.

© AP Photo / John Minchillo Demonstrators hold up signs during a rally for Trayvon Martin, Wednesday, March 21, 2012, in New York.

Martin's death sparked nationwide protests against racial discrimination in the United States. Civil rights advocates marched in over 100 cities, as the incident was seen as an example of racial injustice.

"There is a history of racial disparities in the application of our criminal laws," President Obama said at the time. "A lot of African-American boys are painted with a broad brush. If a white male teen was involved in the same kind of scenario…both the outcome and the aftermath might have been different."

The altercation with Martin was not Zimmerman's only incident of violence. Last month, the 31-year-old was arrested in Lake Mary, Florida, on suspicion of aggravated assault and domestic violence. He was also arrested on similar charges in late 2013, after throwing a wine bottle at his girlfriend.