Replying to Skating with police

So we just got back from DC and we were at freedom plaza , a really known skate spot simliar to love park. We saw two kids who were filming scatter and they hid all there stuff. This policewomen came around the corner and saw my friends board sitting next to the car. Question is, he didnt stand on it, he didnt touch it.She hopped outta the car jogged to the board took it and drove off with it. She said my friend didnt have ID and it was a 50$ fine. What the fuck!