Upon his release he became involved in bootlegging and then drifted into bank robbery in the late 1920s and early 1930s. On June 17, 1933, in a botched attempt to free his friend Frank "Jelly" Nash from the FBI, Miller and two cohorts, supposedly Pretty Boy Floyds and Adam Richetti, ended up killing Nash and five of the law men with him in what is known as the Kansas City Massacre.
After the KC Massacre the FBI was determined to bring Miller in. The hottest man in the USA, Miller found himself unwelcome in the Midwest underworld. He headed east where he was friendly with New York syndicate boss Louis Lepke Buchalter. A Lepke associate named Al Silvers helped Miller with a car and some optometry equipment to use as a front as an eyeglass salesman.
Knowing the Lepke was friendly with Miller, the FBI paid the gang lord a visit and let him know that things could get hot for him if he aided Miller. On November 1, Miller escaped a shootout with the FBI but dumped his bullet riddled car. Inside the auto the FBI found the optometry equipment and were able to trace it back to Al Silvers, who went into hiding.
Lepke had a dilemma; if the FBI caught either Silvers or Miller what might they spill in an attempt at leniency? Silvers was the first to go on November 20. Lepke's boys caught up with Miller in Detroit nine days later. Liker Silvers, Miller was garroted by those he knew and probably trusted. He was then bludgeoned to death with a hammer. His naked body, like that of Silvers, was found tossed on stretch of road covered with a blanket.