Synopsis by Jason Buchanan
Offered some curious and insightful help in their investigation of a young murder victim by her elderly but overzealous landlord, Calvin Lampe (Bill Mustin), Sgt. Joe Friday (Jack Webb) and Officer Bill Gannon (Harry Morgan) notice a missing page from a letter and prepare to take fingerprints that will yield unexpected results. It seems that the only print they were able to lift was Lampe's, and the unlikely landlord soon becomes the lawmen's prime suspect. Shocked to discover that Lampe is a retired deputy chief from Chicago, Lampe explains that, after painting the apartment, he had touched the wall to see if it had dried and that the victim had asked him to add some lines to a letter she was writing. Soon locating the murderer's girlfriend, the fearsome young lass turns state's evidence. It isn't long before the murderer himself -- who killed the girl while robbing her apartment -- is apprehended. Asked by Friday why he doesn't display his police memorabilia in his apartment, Lampe says he didn't want to become his tenant's personal police officer.