You are correct,the police are not allowed to shoot radar or laser from private property.I got stopped here in Columbus,Ohio for the same offense;38 in a 25 zone.I told the officer right on the spot and he told me to get the hell out of there.All places have different laws.Check it out at the local library where you were stopped.Revised code book for the state and city area.If you state to the magistrate that the city/township did not have express written consent to moniter traffic from that lot,he'll have to throw it out of court.Stick to your guns!Do not be intimidated by anyone or you will lose.I've taken five offenses to court and have won all of them.If need be state there was heavy traffic to which his radar was incapable of citing you out of the pack.