Depending on your situation, there are lots of ways to be involved in your area of interest.
(btw, when I took a "civilian" job in corrections the person reviewing my application actually had me complete another one and lie, I acknowledge past pot use, she explained "It's none of their business, the answer is NO."---I came to realize that employers often want the ability to present the work force in a certain light, they don't really care what you have done but how they look, and what they may or may not be held responsible for if something occurs)
Anyway, if you can return to school, this is a field that is growing because the US has 5% of the world's population but 25% of the world's incarcerated. Programs and professions that work at prison/justice reform, research, alternative sentencing etc...
Law is another option (paralegal or an attorney).
If you can't go to school. Consider trying again, coming in to another part of the system and eventually moving...
If you like the moments of "rush", you might like doing EMT work, or something like that.
Whatever you did, you can deal with it and either move on to something else or return---I've known people to go in and out of professions like law enforcement, even people with significant "problems" or missteps.
Mental Health workers are needed also....
But don't beat yourself up over this. You need to walk forward and you will I think.