Bad exchange

It all started on Saturday when I got stuck up a tree while running away from two shady characters. Anyway as I was up there I heard a couple of guys whispering, one of them sounded like a proper ass. Couldn't hear what was being said as there was a lass kicking off nearby. I noticed a small bag of what I assume drugs left on the floor, I picked it up to return it when I fell out of the tree. No sign of the guy though, should I keep it or get rid, it has my fingerprints on it. Any help would be useful.

Thanks