If I have dual citizenship in Canada and the U.S.?
Citizens are still required to present themselves a port-of-entry to be inspected before entering their country. The fact you can cross the border freely in both directions does not change that requirement. So yes, if you cross without inspection and you are caught, you can be detained. You will be forcibly inspected, fined and/or charged for your offense and then let on your way. You will not be stopped from entry but you sure can be slowed down and be made very expensive for you if you dont follow the proper process.