I prefer my .300 win mag when hunting coyotes, i got these this week.

I would say you have a poacher who isnt in it for the meat, you have a couple guys running around who just like to shoot and kill for the thrill of it, they are not hunters, thats for sure. you should see if you can get the dnr to set up a sting with a decoy target. also, set up a trail cam where you think they might be entering the property, most likely they are doing it at night though.