Found an iphone 4 can i activate it?

I found an iphone 4 while i was at a park with my cousin. I looked around but no one came for it and the battery is dead. I know alot of you people say to return it, but the thing is that the park i found it in is in Wisconsin and i live in Chicago.( I was visiting my cousins) It has been about 2 weeks and no one has traced it or maybe its because it has no battery, to far way i don't know. But i was thinking of use it for my self like maybe activating it if possible. I know i will feel bad, but whatever you know. So is there a way to activate it with a different company or some how? Also i don't want to turn it on because i'm afraid that if it turns and maybe i get in trouble and the police thinks i stole it. Can some one just help me? P.s. I don't trust the police with it because i don't think they even look for the person it belonged to. I bet they ask 5 people then keep it to themselves.

Yes it can be traced by the cops.