That's criminal trespass in any State. You can have your neighbor fill out an affidavit of fact that you can get online or from a third party debt collector (attorney) and have him serve it to the County Sheriff. The local police will not act on it. The Sheriff must. It will be notarized properly and becomes a legal document with weight. They must act on an affidavit, they can choose to act on a complaint.
Considering the state you live in, It wouldn't surprise me if you would be liable for a criminal's injury while trespassing on your private property.
Is your fence posted? PRIVATE PROPERTY FOR PRIVATE USE is a very clear message that is common law.
You could treat your neighbor to lunch for being a good guard while you were gone and stop in and talk to the Sheriff. He or she has the power to stop your out of control policy enforcement thug.
Out here that guy would be classified as a training accident.
My GSD is smarter than your honor student.