The down side of this whole deal is that you will be devoting time effort and energy to the negativity created by this bozo,for me I wouldn't want it to take away time from my hunting or other things I would rather be doing.
If the dec wont arrest his a-- and you feel a need to ruin this guy's poaching activities,there are a number of ways to ruin his area,without being obvious about it.walking through the area repeatedly,cheap aftershave thrown about the area,you are only limited by your creativity.Unfortunately it is time taken away from productive things you could be doing.It sucks that he is killing that many bucks out of an area that could likely be excellent,(probably killing young bucks to boot).At the very least I would likely walk the perimeter of the guys area and try to cut off his area to get a crack at the best animal or animals the area holds before this guy gets in there.Not really my nature,I would prefer to be some other place where this kind of thing is not an issue.
As an aside,I was at Yankee Stadium last night with my wife and daughter and daughters freind.The Yankees had lots of hitting going on,Jeter,Abreu,and Rodriquez all had three hits a piece.I hate NYC,I hate driving in NYC.We had great seats behind the visitors dugout 8 rows off the field,our daughter and her freind loved it,so I will endure the stuff I don't like for that!