On July 25, 1946, two black couples were riding in a car in Walton County, Ga., when they were mobbed by a group of white men. They were dragged from the car at gunpoint and tied up. Then they were shot — about 60 times, at close range — and killed.

The episode, which became known as the Moore’s Ford lynchings, is considered by many to be the last mass lynching in American history. It prompted national outrage and led President Harry Truman to order a federal investigation, making the case a critical catalyst for the civil rights movement.

Although a grand jury convened and witnesses testified for 16 days, no one was ever charged and the case remains unsolved.

Now, more than 70 years later, what those witnesses said may be on the verge of becoming public.

On Monday, the United States Court of Appeals for the 11th Circuit, in Atlanta, affirmed a lower court’s ruling that had ordered the release of the grand jury transcripts from 1946. In a 2-to-1 opinion, Judge Charles R. Wilson wrote that the event was so clearly of “exceptional historical significance” that “the interest in disclosure outweighed the interest in continued secrecy.”