A close friend and associate of John Dillinger, Pierpont was the mastermind of the Dillinger gang until his arrest in Tucson on January 25, 1934. After Dillinger escaped from Crown Point with a wooden gun, Pierpont tried the same tactic with a gun carved from soap. The plan failed. He was almost totally paralyzed by bullet wounds, and had to be carried to the electric chair.