Int he case of no knowck warrants citizwens, whether guilty or innocent, should be allowed to be legally in the clear shouldthey shoot any and all of the officers dead, so long as no announcement that they were officers were made.
Obviously this assumes they have their weapons legally. Most criiminals would not and makes a lot of this moot, but if they break into the wrong address the citizenry very well may be legally armed. This ensures the cop is responsible for making sure it the correct address or risk forfeiting their life, as should be the case.