Is a nearly scene-for-scene remake of the film I Wake Up Screaming (1941) with Victor Mature and Betty Grable.
The use of the quote, "The butler did it," was at that time a recognized joke. It played off the spoiling of the ending of a play or movie by a big mouth in the audience. It did not refer to the plot of the film being shown in that theater.
In another reference to the movie Laura, this film opens with a view of Vicki's portrait, which looks eerily like Laura's portrait--same pose, same dress--as if Gene Tierney's head was replaced by Jean Peters' head.
The two leads are watching the movie 'Laura' in the theater. Although this movie is a remake of 'I Wake Up Streaming,' it shares similar traits with 'Laura' being named after a beautiful woman whose portrait is seen in the opening credits, and who winds up either dead or presumed dead. Also, both movies has a cop in love with both Vicki and Laura, and they wind up interrogating her male friends, all culprits.
It's notable to see TV's Paladin, Richard Boone, acting with radio's Paladin, John Dehner.