In a bonus featurette titled "Johnny Depp on Set" on the Blu-Ray release of "21 Jump Street," we learn how Depp came to be involved in the movie. It turns out that when the crew approached him about an appearance in the film, he told them that he would only return if DeLuise also returned so that the duo of Hanson and Penhall could be reunited. Thankfully, the filmmakers had been planning to get DeLuise on board and when they confirmed that he was back, Depp agreed to do the part.
According to the featurette, he also wanted his scene in the movie to give a definitive end to his character in the franchise. Thus, the scene featuring Hanson and Penhall's final stand was born. While it's a bit sad to think that Depp won't be involved with future endeavors in the "21 Jump Street" universe, it was a treat to see him go out with a bang — and with his old partner at his side, no less.
