Actually, the way the law is written in most of the US, if an LEO “even illegally” breaks into your home and you shoot him, you have committed a crime. It does not matter if they are not uniformed, have not identified themselves, have not knocked, or followed any other “typical” police entry rules.
This has however, become an issue in the state of Indiana.
May 13, 2011 - “Overturning a common law dating back to the English Magna Carta of 1215, the Indiana Supreme Court ruled Thursday that Hoosiers have no right to resist unlawful police entry into their homes.”
Importantly, the only difference in this case was that their state supreme court officially recognized what much of the rest of the country has been doing, and this was “the straw that broke the camel’s back”. Less than a year later:
http://www.therepublic.com/view/story/63dffc10822d468eab13fda64bcfffee/IN—Police-Unlawful-Entry/
March 21, 2012 - “The measure specifies that people are protected by the state’s self-defense law if they reasonably believe force is necessary to protect themselves, someone else or their own property from unlawful actions by a public servant.
“The legislation was passed by strong majorities in the House and Senate and signed by the governor.”
Importantly, though, this only applies in one state as of now, so in the other 49, citizens *may* be held criminally liable for defending their home. If it is a criminal, they are likely free and clear. If it is an identical looking individual who happens to be a LEO, they could be arrested for murder.
That is what I’d expect to happen (not rightfully.. just what I see happening) however, if the home owner even farts to loudly and it’s considered a “shot fired!!!” There won’t be a home owner to charge with anything.
That home owner will have 40+ holes in him and will be at the morgue.