They can only shoot if the offender threatens somebody's life. That is, if he has already murdered somebody and now is running away, the police have no right to fire because while he is on the run, he is no threat to anybody. They are so proud of being a law-abiding nation. They walk around smiling at each other. People drive slowly observing some mysterious limitations.
Nothing can be easier.
And none of it has anything to do with a 200-year long history of democratic traditions. Police in America have no right to shoot into the thin air. Once you've drawn your gun from its holster, you must hit the target. Each type of police wear their own insignia on the sleeve. This is if you pass yourself as a moose-protector.