The Untouchables S04 E07 The Eddie O'Gara Story

"The true story of FBI man Eliot Ness's savage war on the notorious mobsters Al Capone left behind!"

Chicago. Right after the St. Valentine's Day Massacre. (February 14, 1929.) Ness and his men are scouring Chicago, looking for Bugs Moran.  Ness says there used to be 2 gangs in town, now there's just one.  Ness figures if they get to Moran first, maybe he'll talk-- he might just be mad enough to give them the information they need.