Originally Posted by bronco67

If the dog hated him his throat would be ripped out.

What is his favorite treat? Every dog has one. Get Killer to accept the treats from the guy with successive approximation. Leash him up and have the guy stand about 10 feet away. Get him to put the treat on the ground a few feet away from you and Killer, and then he can walk back to his spot. Take Killer over to get the treat. Keep doing this for a while, then shorten the distance, until Killer takes the treat from his hand. But don't do it in only 2 or 3 moves. Take it slow.

I trained my dog with successive approximation to get him over any anxiety or fearfulness he's ever had.

If Killer bites his hand, you probably shouldn't own a giant dog. Killer is fearful of this guy for some reason. Or maybe he looks like prey because of his body language. When someone acts scared of my Lab, he goes into predator mode instantly and I have to check him quick before he does something rude.