In the end credits it says that this episode was dedicated to the memory of Sunni Walton O'Neil, an animator for The Simpsons.
When Bart looks through the police records, he finds Homer's and comments, "Wow, Homer's been in jail six times." Originally, the line after that was, "Aw, he killed a swan at the zoo," but the line was changed to "Aw, Mom's only been in jail twice." The resulting line change raises questions of how Marge's arrest information can be on Homer's police record.
The scene where Bart tries to call the abandoned Morningwood Penitentiary to warn that the electric chair is on, an officer is on the phone to his wife Martha, with a sign that reads "Cell Block H". Which may be a reference to the late 70s, early 80s Australian soap opera "Prisoner: Cell Block H", which aired in the United States. The officer also resembles a few officers seen on Prisoner: Cell Block H.
Previous Episode References
Bart's line about Marge being in jail twice is a reference to the season three episode "Homer Alone" (where Marge was arrested for obstructing traffic after having a nervous breakdown and stopping her car in the middle of the road) and "Marge in Chains" (where Marge is put in jail for absentmindedly shoplifting bourbon).
As Troy McClure is talking and the Simpson family is on the Knowledgium runway, Maggie's bow is colored yellow.
When Homer is playing the "Let's Make a Baby" video game: the announcer says "You are out of sperm." The closed captioning reads, "Your score is zero"(This may be caused by a change in the script or ad-lib that was not passed on to the closed caption people).
When the Simpsons are at the museum, Bart says he's going to go toss the virtual salad, but the closed captioning says "I'm going to crawl inside the Invisible Frenchman."
The door leading to the electric chair initially has " Danger" written in red text, but after Bart opens the door it is written in black text.