Mama's Boy

A man walks into a hotel lobby, takes a gun out of his briefcase, and shoots the desk clerk. The gun had a silencer which suggests a professional hit. The man was new to the job and the house detective got off a couple of shots, but is not sure of what he saw. The gun traces back to a known felon, but more information is needed. Finally the house detective recognizes the gunman and Frank starts to look deeper into the murdered man.