 I went down the same rabbit hole, and there is nothing that really tells you exactly what caliber it is. I thought they would have let it out by now because we did have a deceased person there. Could you tell by the New York Times photo where it's the trail of the bullet after Buzzweiser's head? Does that give any? No, I don't think so. But just like he was pointing out, the small wound that I saw, it reminded me of a .22 rifle.