Given how long it has been, it won't be as much of an issue as if it were a couple years. Was the charge a felony or misdemeanor?
Your military service will also help as long as you kept your nose clean.
That being said; the conviction along with your age (I know some of my local agencies won't consider you if you are over 36) will put you at a disadvantage against younger applicants with no foibles in their past. But if you're still in military shape, that will help.
You lose nothing by applying though.

