Since I am a police officer, I can assuredly tell you that the police are usually not interested in recovering discarded contraband. Maybe a large amount such as a brick of marijuana but not a small amount that came out of someone's personal stash. There's nothing wrong with scattering the contents of the bag to the wind and going on your way. I definitely would not recommend carrying the marijuana anywhere. If discovered in your possession, the "I found it" explanation likely would not fly.
As far as awareness of geocaching, most of my fellow officers would have no idea of the concept. I've introduced geocaching to one other guy on my shift who is pretty into it now. The others on my crew just don't get it. We are paid to be suspicious of people. If you are found geocaching late at night, prepare to be scrutinized.
