Jefferson Keane is executed halfway through the first season because the actor portraying him, Leon, refused to commit to a series. When Leon asked Tom Fontana why he was being killed off, Fontana told him it was because he said he wouldn't commit to more than four episodes. Leon replied that he thought he'd been talked out of that and actually wanted to stay.
Actor-Shared Background: Both Anthony Chisholm (Redding) and John Doman (Galson) served in The Vietnam War, as did their characters. Chisholm was a platoon leader and Doman was commissioned second lieutenant in the Marines.
Cast the Expert: Chuck Zito (Pancamo) and Craig muMs Grant (Poet) were the only cast members who had actually done time in prison.
Cast the Runner-Up: Chuck Zito (Pancamo) first auditioned as a Biker, having being a veteran member of the Hell's Angels Biker Club. However because of his complexion and heavy New York accent, Tom Fontana thought he'd fit in better with the Italians on the series.
muMs the Schemer wrote every one of the poems his character Poet recited.
The basketball tournament allows real-life pro ball player Rick Fox to show his skills.
Prior to the boxing scenes in season 3, Tom Fontana asked the actors involved if they had experience boxing. All said yes, but it turned out that only Chuck Zito had ever done any actual boxing.
The talent showcase episode showed off the pipes of a number of the cast members, almost all of whom had band or Broadway experience.
Bonus points to Rita Moreno (Sister Pete) who has an Emmy, Oscar, Tony, Grammy, and Golden Globe for her singing roles.
Terry Kinney (McManus) and Kathryn Erbe (Shirley Bellinger) were married for 13 years and have two children together.
J. K. Simmons' spouse Michelle Schumacher made guest appearances as Norma Clark. Their characters don't interact in any way, but Vern notes that Norma's letter is "stinking with cheap perfume" during a mail delivery scene.
Irony as She Is Cast: Mike Doyle plays the intensely homophobic Adam Guenzel in season five. In real life, Doyle is openly gay. Similarly, Aryan biker Hoyt is played by the Jewish Evan Seinfeld who even has a Star of David tattoo on his stomach.
Željko Ivanek asked to play a villainous character in this because he was fed up with being type-cast as dull nice guys or Reasonable Authority Figures. His subsequent career proves that it worked.
Bill Fagerbakke as the sinister corrupt prison guard and Neo-Nazi Karl Metzger.
Post-Script Season: Tom Fontana was convinced that season four would be the final season, so he wrote two endings: one where Beecher got paroled and one where he didn't. If the show was canceled they would end on the happy note of Beecher being paroled.
A very large number of the actors also played main, recurring, or guest characters in the Law & Order franchise. This is likely because both series were filmed in New York rather than California, so it pulled from the same pool of actors.
Dean Winters (Ryan O'Reilly), Lee Tergesen (Beecher), Kristin Rohde (Clare Howell), Željko Ivanek (Governor Devlin) and Edie Falco (Diane Whittlesey) had all played recurring or guest roles in Homicide: Life on the Street, which Tom Fontana had played a major production and writing role in.
Resident Manipulative Bastard Ryan O'Reily (played by Dean Winters) and his mentally retarded older brother Cyril O'Reily (Scott William Winters) are brothers in real life. Their eldest brother, Bradford Winters, was series creator/head writer Tom Fontana's main collaborator for most of the series' run, as well.
Ernie Hudson's son Ernie Hudson Jr. made recurring appearances as inmate Hamid Khan.
Reality Subtext: Chuck Zito (Pancamo) and Craig muMs Grant (Poet) were the only cast members who had actually done time in prison.
Role-Ending Misdemeanor: Some cast members that played prisoners have noted that, throughout the series, if you showed up late to the set, your punishment would be that your character would either die or be raped the next week.
In season 3, one of the inmates writes his memoirs. He saves it on a disk, which is then intercepted. Today, the file would be sent via email or online submission form, and stored elsewhere.
Early in Season 5, Beecher's computer gets upgraded...to 128MB of RAM (which was slow even in 2002).
Wag the Director: According to Tom Fontana, Dean Winters had a crush on Luna Lauren Velez and requested a sex scene to be filmed with their characters. A scene in which O'Reily fantasizes about having sex with Nathan was filmed much to Winters' delight.
