On September 16, 1920, a horse-drawn wagon packed with 100 pounds of dynamite and 500 pounds of heavy iron sash weights detonated outside the J. P. Morgan bank building on Wall Street.
The blast killed 38 people, injured hundreds, and reshaped American law enforcement. Amid the horrific wreckage and chaos, investigators led by William J. Burns faced an immediate challenge: identifying the unknown driver and cart used in the attack.
Because the explosion atomized much of the wooden wagon, physical evidence was severely limited. However, detectives recovered a crucial piece of forensic evidence from the scene—a worn, unexploded tip of a specialized horseshoe detached from the horse's hoof. Federal agents and NYPD detectives visited thousands of blacksmith shops across New York, New Jersey, and Connecticut, searching for the artisan who forged that distinct shoe.
Their painstaking legwork eventually led them to a blacksmith in Manhattan who remembered shoeing a horse for a suspicious man matching the cart driver's description shortly before the blast. Though the driver vanished and the bombing was never officially solved, the meticulous forensic analysis of the horseshoe tip marked a crucial turning point in early federal criminal investigations and forensic reconstruction.