The District Attorney is dressed up, and even acts a lot like 1950's attorney Perry Mason.
Sideshow Bob's line, "And I would have gotten away with it too, if it weren't for these meddling kids" is from Hanna Barbera's Scooby-Doo.
The entire idea behind the Itchy & Scratchy cartoons is nothing more than an "extremely violent" version of the old Tom & Jerry cartoons. Their names, however, were inspired by the 1958 cartoon Pixie & Dixie.
The cover of Timely Magazine showing a picture captioned "Krusty - Krook of the Year" is a pun on Time magazine's annual Person of the Year issue.
A magazine called News Weekly is shown which is a parody of the magazine Newsweek.
First episode to focus on a supporting character rather than a Simpson family member (It focuses on Krusty the Clown).
First appearance of Judge Snyder although at this stage in the series he is known as Judge Moulton (as mentioned in Bart Gets Hit By a Car) and has a Caucasian appearance and a higher voice.
This is only one of two episodes on the Season 1 boxset to end with the original 20th Century Fox Television logo that was used on the first three seasons of the show. The only other episode to have it is "There's No Disgrace Like Home". Every other episode has the 20th Television logo.
This is the second and last episode to show Chief Wiggum with brown skin and black hair (the first being "The Telltale Head") although he is later shown with black hair again in several episodes from season 3. (Also, a flashback of the end of this episode featuring him with Krusty and Bart was shown in "Like Father, Like Clown".)
When Apu says "You can emerge now from my chips. The opportunity to prove yourself a hero is long gone. ", his left arm is missing.
Sideshow Bob refers to The Death of a Titan as Chapter 35 of The Man in the Iron Mask, when in reality it is chapter 50. He could have been reading an abridged edition.
When Chief Wiggum orders the police to arrest Sideshow Bob (after being accused for framing Krusty), his skin is white until after Krusty is released from prison, when he and the police apologize for the misunderstanding.
Krusty says that he is illiterate but in later episodes, he is shown reading out stuff. He could have learned how to read to some degree between this point in time and then, or he may have been lying about his illiteracy all along.