The Man Who Dared (1946)

The screenplay was adapted from a radio script by Maxwell Shane and Alex Gottlieb and first shown as the bottom-half of a double feature with the top-billed "Without Reservations" at Hollywood's Pantages Theatre: A newspaper columnist, against capital punishment and crusading against murder convictions based on circumstantial evidence, tampers with evidence found at a murder scene in such a manner that it leads to him being accused of the crime, convicted, and on his way to the state prison to be executed. The tampering was to prove a point about circumstantial evidence, and he succeeded in proving that circumstantial evidence will indeed get one convicted, but now he must prove his innocence, which he is in no position to do.