The time that Al Capone’s criminals wore cops uniforms to trick their targets has become so iconic that few remember that the hit was actually a failure. Al Capone was after Bug Moran and his gang.
Dressed as cops, Capone’s men raided the gang when they were bootlegging. When they gave up their weapons, the gang were machine gunned down. Bug Moran, however, had seen the ‘cops’ arrival and had taken off.
But Al Capone should have worried less about other gangsters and more about the government...