First of all, they shouldn’t ask.
“As a basic principle, we can’t tell you to stop recording,” says Delroy Burton, chairman of D.C.’s metropolitan police union and a 21-year veteran on the force. “If you’re standing across the street videotaping, and I’m in a public place, carrying out my public functions, [then] I’m subject to recording, and there’s nothing legally the police officer can do to stop you from recording.”
“What you don’t have a right to do is interfere,” he says. “Record from a distance, stay out of the scene, and the officer doesn’t have the right to come over and take your camera, confiscate it.”
Officers do have a right to tell you to stop interfering with their work, Burton told me, but they still aren’t allowed to destroy film.