Can you be an officer, and still become a PJ in the USAF? Or do you have to be enlisted?

If this is possible, then what are the training requirements for becoming a PJ? This is something I really want to do, after graduating from the USAF Academy. Becoming a PJ is a dream of mine, and I just want to know if you can be a PJ as an officer, or do you have to be enlisted to become a PJ?