And that’s the difference. All the people citing pneumatic hammers are off-base. A pneumatic hammer has far more force than the strongest man, weilding a sledgehammer could muster.
The claw end? I live near Methuen, MA and there are at least six shelters within 20 miles, where he could have surrendered the dog, to be humanely euthanized at no cost.
The claw end would insure penetration of the cranial vault, with subsequent immediate cessation of consciousness.