2d Circuit Holds Lawfully Possessed Gun Does Not Constitute Probable Cause
blog.simplejustice.us
blog.simplejustice.us
This varies by state. Whether required by law or not, though, carry permits often show up when the police run the license plate so handing over the carry permit along with driving license is good sense. It also shows the cop that you're not trying to hide anything.
The whole point is that cops' powers need to be bound and restricted. Too much relies on "good sense" and politeness. It creates room for discrimination and bias.
[1] https://en.wikipedia.org/wiki/Killing_of_Philando_Castile