First appearance of "Happy Hound", later (and better) known as Droopy.
The cartoon starts out at Swing Swing Prison - a take-off of Sing Sing Prison in Ossining, New York. Also, the text over the prison gate reads "Crook of the Month Club", referencing the (at the time) popularity of Book of the Month clubs.
In the newspaper announcing KILLER CAPTURED, readable items include "Laughs Of The Week" with a joke asking the difference between a worm and a bedbug (A worm crawls on its own stomach, while a bedbug is not so particular.) and part of a poem by Henry Wadsworth Longfellow (There was a little girl, Who had a little curl, Right in the middle of her forehead. When she was good - The unreadable remainder of the poem is: She was very good indeed, But when she was bad she was horrid.) There also is a spoof story about a man laughing himself to death in a magic shop.
First Droopy cartoon produced in the Hanna-Barbera era from 1943 to 1958.