As someone who had more to deal with the police than he actually wishes...

Usually there is never an officer who ask you. Also if they ask you for a pin, then they took the phone from him without any form of (legal - yeah added it extra cuz law is f0cked up different in every country/state) warrant, then its their own fault.

And in this special case I am very interested how it would end, because if I would ever visit the states, I wouldn't bring even my main phone...