sentences:  After Nitti was shot and nearly killed by Chicago police detective Harry Lang in December 1932, his suspicions towards Winkler only intensified.After Gus Winkler was observed making visits to the Bankers Building office of FBI agent Melvin Purvis in the summer of 1933, Nitti decided to act.While Winkler was only giving the feds tips on Kansas City Massacre suspect Verne Miller, Nitti believed that he was turning informer.