Incidentally, Oz is also sort of a spin-off of HLotS. The same way that The Wire came about because they wanted to explore the police strategy more indepth than they could on HLotS, Oz came about because Fontana wanted to explore what happened to the criminals once they left "the box" (the interrogation box) and went to prison. So, a ton of the same actors show up on all three shows. I think every single actor in Oz had been on HLotS. (Beecher was a cop & Keller was a bounty hunter on HLotS. Heh.)