Ironside S08 E13 Fall of an Angel

"«The chief of detectives!»"

A retired assassin kills the son of a mob chief, and tries to escape town after anonymously leaving his own young son in the care of Chief Ironside. The Chief soon puts two and two together, and figures out who the boy is; but he still has to find the father, before a major league gangster out for revenge can get to him first.