Jay-Z's lyrics: And I Heard "Son do you know what I'm stopping you for?"/"Cause I'm young and I'm black and my hat's real low?/Do I look like a mind reader sir, I don't know/Am I under arrest or should I guess some mo?"
Analysis by Prof. Caleb Mason: A great question, and an important one for any future suppression claim. As new lawyers learn (to their dismay), there is no constitutional problem with arresting someone for a traffic violation, no matter how minor. And if you are arrested for a traffic violation, your car can be impounded and then searched to inventory its contents, without a warrant and without any level of suspicion that the car contains contraband. Your person, clothing, and bags can also be searched with no required quantum of suspicion. On the other hand, if you are not under arrest, the police need probable cause to search the car. So if the cop tells you you're not under arrest, and then proceeds to search the car, you will be able to suppress any contraband if you can show that there was no probable cause for the search. Here again, documentation will be important.