On August 14, 1962, a man in a police uniform stopped a mail truck headed for the Federal Reserve Bank in Boston. What the postal worker behind the wheel didn’t know was that the officer was an imposter, the truck was filled with $1.5 million and the largest cash heist in history up to that point was underway.

Brandishing guns, the “policeman” and another man wearing civilian clothing stormed the truck, which had just left tourist-laden Cape Cod. The thieves forced the mail employees out of the truck and onto the highway, where they were bound and gagged. They then threw their captives into the back of the truck and took off.

According to the employees, the hijackers, who called each other “Buster” and “Tony,” stopped twice to unload cash before dumping the truck and the people inside just outside Boston, some 60 miles from Plymouth, Massachusetts, where the robbery occurred. By the time the hostages escaped, Buster and Tony had already made their getaway.

Because of the carefully chosen location of the heist, there were no witnesses. A 15-foot-high median strip prevented southbound motorists from spotting the suspicious happenings in the northbound lanes, where the truck was stopped. Buster and Tony—or their accomplices—placed stolen detour signs about four miles south of the truck to reroute traffic behind them.