The killing of top Cuban militant and underworld legend Aldo Vera has never been officially solved.

Gunned down on the street by unknown assailants as he stepped out of a bakery in the barrio called Puerto Nuevo—he was on his way to a meeting of an anti-Castro political group at the time of his death—the killing involved plenty of suspects but few clues. Vera’s has become known as the Cold War cold case nobody could crack.

His murder is the kind of thing JFK conspiracy theorists argue about in their spare time: a controversial moment in history that’s also a compelling whodunit. Vera played a part in some of the more outlandish and violent episodes of the Cold War era—including working as a spy for the FBI (PDF) and probably the CIA, involvement in the bombing of a Cuban airliner, and allegedly being tied to the Kennedy assassination.

Now a landmark ruling handed down last month by a three-judge panel of the U.S. Second Circuit Court lends new urgency to solving the mystery of Vera’s death.