I'm looking for a case where the vehicle location was challenged. My son was charged with 90 in a 70km zone. He insists that he was in the notice zone advising 70km ahead. He says he was actually doing 102 in a 90, he saw the OPP activate his lights while he was still in the 90 zone. The OPP dropped the speed from 102 to 90. The OPP pulled over near the 90 to 70 sign. We are going to ask for a dash cam in disclosure, are there any cases on this defence