Either turn him in or stick an anonymous letter in his mailbox telling him to put $1000 in unmarked $20's in the bag within 24 hours or else.
If its his land just forget it. If not if he has permission forget about it also. Messy any way you go. Good luck!
What you should have done it to take pictures. Then use them for blackmail - not only could you continue to hunt the farm, at least until the statute of limitations ran out, but you might even squeak a grease out of the shooter!