Per dadiOH:

IMO, the answer to my rhetorical question is either that he gets his jollies
killing things and/orhe is trying to show the world he actually has cojones.

I have to repeat my original comment - and not totally tongue-in-cheek:
"I have to wonder if he beats off to photos of him and the carcass."

I was riding my bike in Germany a bunch of years back and I came upon
this guy standing next to his totally-decked-out Mercedes expedition
jeep/SUV, sighting through the telescopic lens of a rifle though a chain
link fence at a doe that was maybe 10 feet away.

*Something* was going on there.... I have no clue what it was, but would
bet that it was certifiably weird.
--
Pete Cresswell