Two men leave a bar, one after the other. Joe Garcia had a record for mugging, but Hummel lures him down an alley, then tells the beat cop he has killed him because he had been attacked. At the coroner's inquest, Frank recognizes Hummel because he'd accidentally killed a mugger a year or two earlier. When Garcia's girlfriend complains no one is investigating, he decides to look into it. (thetvdb.com)