Al capone did ban his guys from selling drugs he said so in an interview, mcgurn got killed while capone was in jail for taxes, tony accardo sponsored mcgurn, nitti and ricca warned mcgurn about selling drugs but he did'nt listen

"McGurn likes you, so I make you. So you are now one of us, if you fuck up, we take it out on McGurn. He is your sponsor. Fuck up, it's his ass. You work in his crew, he is your capo."