Note that the duo were headed to school armed. Why? Planned a school killing spree, and shot the cow as a warmup? The arrogant bastards should be branded extensively, then skinned and made into belts, while their families pay the farmer triple damages on the $45,000.
When i went to High School in central Florida 40+ years ago, it was not against school rules to to have rifles in your vehicle on the the school parking lot. Many students went hunting after school. I have no idea what the current regulations are.