Will a cop make deals for some information?

There was a few fires recently, and I've received a call from the police, asking some question and seeing if I'd be willing to let them take fingerprints. Now I've had no connection with these fires what so ever, just my name was tossed around a bit, but I could point them into the right direction if I pleased as for I have a fair bit of knowledge as to whom they may be looking for, would a cop barter for these names?