When my dad was in JPD in the 70s they got a call one time for an injured horse somewhere....I don't know the details, maybe it had gotten out and hit by a car or something, but nevertheless it was injured standing and needed to be put down. Dad was 6'5" and a certified distinguished expert marksman with a pistol. He told the guy, I've never had to do this before, but show me where I need to shoot it and I'll shoot it there.
So the guy points where to shoot the horse in the head and dad bullseyes it. Horse stays standing. What the hell? I don't know, shoot it again. So he does. I think this continues once or twice more, and by this time it's a gory mess. Horse is still standing. Dad's like I don't know what to do.
Finally Dad looks at his partner, who was five foot something, and says I don't know, you try it. Partner shoots the horse in the exact same spot as dad did. Horse falls down immediately.
Apparently Dad being tall, the angle was wrong, and he was missing the horse's brain. Shorter cop had the correct angle, and down went the horse.