"Many inadequate types do inflict pain, suffering and death on someone other than their primary target and many of them choose children or older women as their victims. It's payback time, and to the perpetrator, who pays the price isn't important as long as the punishment he inflicts makes him feel better about himself- -in control."

Rainsong

So true. It is not at all stretching the bounds of reality to think the offender killed JonBenét as a strike to the heart of her father. It happens more frequently than one suspects. How much easier to kill someone weaker than to perhaps get hurt and apprehended by facing the primary target.