Although this thread is old, a couple points that a few in here disregard or are possibly ignorant about.
.22 is generally the weapon of choice for many poachers
you do not have to have PROOF in order to call the law. you can have suspicion. It's the cops' jobs to gather proof in order to obtain a conviction (D'uh bc).
this guy (the poacher) is an a-hole and not your friend. If he's starvin' let him shoot a doe. either way (doe or wallhanger) it's wrong, but at least if he was a "friend" he'd hesitate on shooting the buck knowing that you and others like to hunt. A starving poacher would have the most humble and ashamed behavior...not email pics,etc
If his kids are starvin then let him pick up cans along the road instead of spending time poaching...I believe he has ulterior motives. He should have been reported