One of the first true tests of this new technology was in the aftermath of the Saint Valentine 's Day Massacre in 1929 . During the Prohibition Era , competing gang members were fighting over bootlegging operations within the city of Chicago . Members of the Chicago Outfit and the Egan 's Rats led by Al Capone attempted to remove all competition from Chicago by eliminating the North Side Gang leader Bugs Moran . The massacre missed Moran , who was not present , but killed seven members of the North Side Gang . The murderers attempted to cover up their crime by posing as police officers , even dressing in police uniforms . Witnesses saw two " officers " leaving the scene , which implicated the Chicago police department as the perpetrators of the massacre . High levels of police corruption during that time period made it seem likely that the police department committed the killings . The investigation stalled until December 1929 when Fred Burke , a member of the Egan 's Rats , shot and killed a police officer in St. Joseph , Michigan . Officers searching for Burke were led to a home in nearby Stevensville . While Burke was not there , inside officers found an arsenal of weapons including two Thompson submachine guns . The Chicago police department was contacted and the weapons were brought back to Chicago for testing . Goddard was asked to compare the weapons to collected evidence found at the massacre using his new " ballistic-forensics " technique . After test firing the guns , Goddard proved that the weapons were those used to kill the members of the North Side Gang , absolving the Chicago police department of all involvement . The successful use of Goddard 's technique resulted in the solidification of his place as the father of forensic firearm examination
Saint Valentine 's Day Massacre
Saint Valentine's Day Massacre
Forensic firearm examination