Not an attorney but I don’t think any state in the union would make it legal for you to shoot a trespasser on your land if your reasonable belief is that they are stealing something off your land.
You could confront them and make them leave, and then depending on what took place next your reasonable belief could change into one where you would be justified (your reasonable belief that they will harm you). Consider a book by Massad Ayoob.
What about barbed wire? Dog?