Extended-range door knockers
I don’t play tennis, but I carry several tennis balls in my squad car. “Why?” you ask?
I have walked up to front doors of residences — and continue to do so — on a variety of calls. An officer can stand to the side of the door and announce his or her presence by rapping on the door with their baton or flashlight, but if some guy decides to open up with his AK-47, standing beside the door is not going to help you. So, what do I do with the tennis balls? I find some big tree or wall to stand behind and with my best big-league pitch, I throw these tennis balls at the front door. In other words, they are an extended form of door knocking. I certainly feel a lot safer standing behind a wall or tree rather than by the side of a door.