Although the 1955 killing helped galvanize the civil rights movement, those responsible for Emmett Till's death were never brought to justice. Now, more than 50 years after the black teen died, the FBI says too much time has passed to bring the case to federal court.

In a long-awaited report Thursday, the FBI said that no federal charges will be filed in the brutal death of the 14-year-old Till, who was beaten and shot for purportedly whistling at a white woman.

The Justice Department reopened the case last year after a documentary filmmaker claimed to have found investigative errors and concluded that some people involved in the crime were still alive.

FBI agent John G. Raucci said in a statement that the five-year statute of limitations on federal civil rights violations had expired. The FBI's report was sent to District Attorney Joyce L. Chiles, who will decide if any state charges can be filed. Chiles did not return a call seeking comment.