That metallic “click’ as the trigger is cocked or the racking of an shotgun is all the warning a prep inside my house will ever get....
As far as I know, firing a warning shot will land you in jail. Not only are you only allowed to discharge your weapon to defend your life if you are in fear of it, but a warning shot in a suburban are is depraved indifference to the lives of those in the bullets path (neighbors, etc). I’ve read several stories of people arrested for warning shots here. So follow the law and shoot to kill. It’s the law.