The Department of Justice announced Tuesday it will not file charges against George Zimmerman for killing unarmed, 17-year-old Trayvon Martin in Sanford, Fla., Feb. 26, 2012.

The DOJ said its independent investigation found “insufficient evidence” to charge Zimmerman with federal civil rights violations in the shooting death of Martin.

U.S. Attorney General Eric Holder said the evidence did not meet the “high standard for a federal hate crime prosecution,” but the decision should not end efforts to explore racial tensions in the justice system. This ruling closes the federal investigation.

“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.”

The then 28-year-old neighborhood watchman shot and killed the Black teen—who was walking back to his father’s girlfriend’s home in a gated community after purchasing snacks at a convenience store—after racially profiling and confronting him, and then getting pounded out on a sidewalk.

The DOJ Civil Rights Division and the FBI began investigating the teen’s death shortly after the fatal shooting, but halted the inquiry to allow local prosecutors to proceed. On July 13, 2013, a Florida jury found Zimmerman not guilty of second-degree murder and manslaughter, sparking protests in several cities.

The federal investigation resumed after Zimmerman’s local acquittal. They reviewed the evidence gathered by Florida’s investigation and prosecution, and independently conducted 75 witness interviews and reviewed other encounters Zimmerman had with law enforcement in Florida, the Justice Department said. Federal authorities also retained an independent biomechanical expert who assessed Zimmerman’s descriptions of his struggle with Martin and the shooting.

The investigation reviewed events from the moment of their first encounter through the fatal shooting to determine whether Zimmerman approached Martin in a “threatening manner” or used force against him because of his race, the Justice Department said.

“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,” said acting Assistant Attorney General Vanita Gupta of the Civil Rights Division.

Martin’s family released a statement Tuesday afternoon saying they were “disappointed”’ by the decision.

“We remain poised to do everything in our power to help eradicate senseless violence in our communities, because we don’t want any other parent to experience the unexplainable loss we have endured,” reads the statement.

Martin’s family said they will continue to work with a foundation named after their son, stating, “We will never, ever forget what happened to our son, Trayvon, and will honor his memory by working tirelessly to make the world a better place.”