Correction, in my last post to you, I said across the right side of the child's skull. Without going back and checking again, I think I'm wrong on that point. It was the left side, I think. Again, not certain without going back to check -- and I don't want to look at those autopsy photos again. In any case, which side doesn't matter unless it might bear on the killer's handedness, left or right handed.
I think the crack was from front to rear longitudinally along the upper right side of the skull - above the parietal region of the brain. Right handed - blow from rear. Left handed - blow from front...