Probable Cause to contact a Driver
In most cases, an officer will have stopped you for a violation of the California Vehicle Code where he/she personally observed you driving (ex. speeding, weaving between different lanes, unsafe lane changes, headlights off at night, expired registration, etc…). However, in some cases, officers may contact you even if he/she has not observed you driving. For example, an officer can approach a car stopped on the side of a freeway and question you regarding possible mechanical or medical problems. Another example is when an officer is called to or comes upon a traffic accident. It may even be that a hit and run was reported and an officer is looking for a vehicle that matches a certain description/license plate number or is going to the home of the registered vehicle owner. It is also possible that a third party civilian reported a driver that they believed to be DUI and gave a description to the police. Regardless, once an officer is given probable cause to contact you, if he/she thereafter believes they observe objective symptoms of alcohol intoxication, they can engage in a full DUI investigation.
