Robbery with a firearm?

I am being charged with armed robbery with a firearm and there was no firearm found with my prints or at all. The police claim they retrieved my prints off of some merchandise (a stick of deodarant) in a store which was robbed that I shop at regularly. The perp they claimed robbed the place was in a mask and unidentified and so they are using my prints to establish a case and are charging me with it. Is there anything I can do? ( BESIDES THE OBVIOUS OF HIRING LEGAL COUNSEL WHICH I CANNOT AFFORD) Do you have any advice for me at all?