This is going to chap some people in the wrong way. I have to say it, though... it will likely make police DOUBLY sure they go to the right house:
http://www.infowars.com/indiana-first-state-to-allow-citizens-to-shoot-law-enforcement-officers-2/
http://www.infowars.com/indiana-first-state-to-allow-citizens-to-shoot-law-enforcement-officers-2/