I'll bet when this nut is found, he will have a SCOPE on this rifle that is worth MORE than the gun.
The primary piece of equipment in this guys hands he treasures more is the SCOPE it allows him to have an "Eye of G-d"...and the rifle is secondary...it is only the means to deliver his "calling card".
Yup, if this guy spent any time on any reputable gun forums he'd KNOW you can't kill anybody with a .223 /sarcasm.
Lots of folks posit that if this guy was "skilled", he'd be wingin' .308s - but 308s leave intact bullets, unlike softpoint 223 rounds. With proper shot placement - clearly within this killer's ability - 223 is obviously lethal.
Add the low recoil, reduced noise and flash, and this guy looks more like a trained perp every day.
223 is absolutely not - necessarily - the choice of the amateur.