Another vote on reading your lease. Chances are there is some kind of clause that tells what they will do and in what order, usually beginning with some kind of notification sticker. If they didn't post the notification per the rules in the lease, you have them by the short hairs.
Also, do you register your vehicle with the apartment for some kind of parking sticker? If so, they should have notified you before the tow.
You are a paying tenant who is legally parking on the property. If you had no sticker and they thought it was abandoned they should have called the police, who would then impound the vehicle after placing the required notifications for the required amount of time (i.e. window stickers for 24 hours). If the apartment had it towed as abandoned when it really wasn't, especially if they didn't take the time to properly notify you, then you may be able to really rake them over the coals becasue now you're into auto theft territory. Add in a gun being involved and it becomes a federal thing.
Are you a college student? If so, I bet your school has a student legal center that provides free services.
Brad