Nice essay. My dad was a police officer too so much of what you wrote resonated with me. The tips apply to everyone: police are trained to constantly look for anything out of the ordinary (and pounce into action with little time to think if it's not so the responses are almost reflexive). Mainly police look for unusual behavior or someone. A white MD friend of mine used to get pulled over often because he had an old klunker that didn't seem to "fit'' in his neighborhood. So when the blue lights flash everyone kind of freaks out and needs to freeze. My dad taught me when he was a kid, the mere sight of a police car made everyone freeze (worrying about getting in trouble).