Can you tell us what parts of the US that might be? I was always taught that although some places have the "castle doctrine" which says people have no requirement to retreat from danger in thier own homes, self defense could only be claimed if a "reasonable person" would be in fear of death or grevous bodily harm to themselves or others. You can`t shoot people just for trespassing.
In Louisiana, you can shoot any intruder in your home. The assumption is that anyone brazen enough to come into your house is looking to cause you bodily harm.
I believe the same is true in Texas, although I haven't paid that much attention since I no longer own a handgun. Too risky with kids in the house to have one ready to use. One with a gun lock on or in a safe isn't much use for a midnight home invasion.