A great many of the gangsters I met were pretty childish. I get awfully sick and tired of a lot of the gangster stuff that I see where everybody is growling at somebody and being the toughest guy in the world. These fellows were not that way. They were just like kids. We had fun doing it. When we conceived the idea that these fellows were childish, it helped us do some scenes. For instance, Ben Hecht wrote Muni a scene when I told him I thought we ought to make a good scene out of when Capone discovered a machine gun. Ben said, “What do you mean?” I said, “Well, can’t you write a scene like a kid finding a new toy?” “Oh yeah.” And he wrote a marvellous line.

Howard Hawks, in Joseph McBride, Hawks on Hawks, University of California Press, Berkeley and Los Angeles, 1992

It’s important to remember that Howard Hawks is a moralist. Far from sympathizing with his characters, he treats them with utter disdain. To him, Tony Camonte is a brute and a degenerate. He deliberately directed Paul Muni to make him look like a monkey, his arms hanging loosely and slightly curved. (…) The most striking scene in the movie is unquestionably Boris Karloff’s death. He squats down to throw a ball in a game of ninepins and doesn’t get up; a rifle shot prostrates him. The camera follows the ball he’s thrown as it knocks down all the pins except one that keeps spinning until it finally falls over, the exact symbol of Karloff himself. (…) This isn’t literature. It may be dance or poetry. It is certainly cinema.
François Truffaut, I film della mia vita, Marsilio, Venezia 1978