Need to look carefully at the laws for each state. Shooting in self defense is always justified. Shooting to protect property not always so.
State law and local law is overridden by the constitution on this, Everyone has the absolute right to protect life, liberty, and PROPERTY by any means necessary or available.
Since when did private property become public community property in common regulated by laws implemented for enforcement of public property? As soon as they passed over the property line THEY lost all rights and legal protections, including all law enforcement without a WARRANT.
So what do local municipalities and states do? They claim to only recognize private property if it is fenced, locked, and posted. Then they tie your hands with an ordinance against fences tall enough to keep the public out. They force you to make yourself a vulnerable victim and then charge you when you do become a victim of trespassing.