The brutal murder of Emmett Till, a black Chicago teen, in Mississippi nearly 63 years ago went unpunished, but not forgotten. A decision by his mother, Mamie Till-Mobley, to allow an open casket at Emmett’s Chicago funeral was an act of defiance as well as mourning, helping to ignite the modern civil rights movement. “Let the people see what I’ve seen,” she told the funeral director.

“I think everybody needed to know what had happened to Emmett Till,” she said in a PBS documentary interview. Those words ring loudly amid news last week that the U.S. Department of Justice has reopened an investigation of the 1955 slaying.

Many horrific details of Till’s death, including the racist intent and identities of the killers, are known. What’s missing is closure. And justice.

Emmett was 14 years old in the summer of 1955 when he was put on a train to visit relatives near Money, Miss. The story told by a 21-year-old white woman, Carolyn Donham, was that Emmett propositioned and whistled at her at a corner store. Days later, Emmett was abducted. His body was found in the Tallahatchie River, weighted down by a cast iron cotton gin pulley. He’d been beaten savagely and shot in the head.

The case was a sensation. Photos of Emmett’s mutilated body shocked America. Two white Mississippi men, Roy Bryant and his half-brother J.W. Milam, were acquitted of the murder by an all-white, small-town Mississippi jury that deliberated for a little over an hour. Rosa Parks said she had Emmett Till in mind in December 1955 when she refused to move to the back of a bus in Montgomery, Ala.

A month later, Bryant, who was Donham’s husband, and Milam admitted their guilt to Look magazine.

The pair are dead, as is Emmett’s mother, but Donham is alive. About a decade ago, the Justice Department and Mississippi prosecutors reinvestigated the murder; they declined to move forward. A year later, though, Donham talked to writer Timothy B. Tyson and said she hadn’t been truthful in her trial testimony. Donham’s interview could be the reason for a renewed federal investigation, according to the Associated Press.

We hope it all means the nation one day soon will know all the facts of what happened to Emmett Till.