From the article:

Roop later told police that he shot Rainey in the head “for effect” and that he had three no trespassing signs on his property. Roop said he feared for his life.

“I’m not going to give him the chance to do something to me,” he told police. “I was in fear.”

What a load of crap. It was a cold-blooded execution of a completely innocent man, and this knuckle-dragging cretin is trying to hide behind that idiotic SYG law.