In real life? It's not possible. No one has EVER escaped ADX Florence, and we're talking about some of the biggest names in crime: Ted Kaczynski, El Chapo, some of Al Qaeda's top brass, literal spies who were caught, and serial killers. And if those guys, with the connections and IQ they have, can't even bust out of ADX, then there's no way Joker can. Honestly, if the DC Universe were realistic in any way, Joker would've been sent to ADX a long, long, long time ago, and his insanity defense wouldn't even work.
