As far as I understand the facts, it all seems very much like any loser could have pulled this off. It doesn’t take much training with a rifle to make the shot.

I’m a little perplexed about “engraving” on the cartridges…that seems…tricky and harder than a sharpie marker.

But that aside, everything else is pretty simple for anyone who has shot a dozen or so rounds with a rifle at a target.