The Untouchables S03E27 - Arsenal

Frank Nitti and Bugs Moran are about to go to war, and to forestall that possibility, Elliot Ness and the Untouchables begin rounding up every machine gun owned by the gangsters' hitmen. To resupply himself, Nitti hires Polish gunsmith Jan Trobek to make a dozen Tommy guns. Unfortunately for Trobek and his wife, Nitti and Moran soon settle their differences, which means that the pair are now witnesses who could turn into liabilities for Nitti.