Ryan--I can only add to the insightful comments made by everyone else. You're still young. A lot of agencies prefer someone just a little older probably more around 25 yoa age or so.
As far as your past chronic problem with poor decision making,......this could pose a problem for you but I would not say you're permanently out of the picture. And yes, realisitic PD's are not out there trying to hire Jesus Christ to be a cop! :D No one is perfect and PD's know that it is quite common that we've all done things as kids growing up. BUT, it depends upon over all what you've done and the circumstances. Some departments can be more forgiving than others with these issues.
Your best bet is in my opinion to:
* Get some more schooling under your belt.
* Wait a few years before applying for a PD job.
* Contact the PD recruiter you have interest in and find out if your past indiscretions will be a serious issue or problem. If it will, to hat extent? it may give you a better feel of where you stand before putting in all the time and effort in trying to land the job.
* And stay out of trouble in the meantime!
That's how I see it. Good luck!
Charlie
"Good and evil are present in this world, and between the two there can be no compromise" - President George W. Bush, in his farewell address to the nation.