That small pistol doesn't have enough flat surface areas to get a full,unsmeared, identifiable clean print. If you touch something and touch it again fingerprints overlap and they're worthless. They didn't have very sophisticated means of fingerprinting and zero DNA testing then either. Not like today where they'd use the super glue vapor in a chamber to stick to the oils left behind with the print or computers that can match prints. And even then it's very hard to get clean prints and they aren't enough to convict someone of a crime in court if that's the only evidence. I'm sure the waiter wouldn't have identified Micheal or he would have "disappeared". Tom wouldn't have allowed Micheal to be fingerprinted or they would have gotten the prints throw out, etc.