$1:
"What 10- or 11-year-old child goes to Costco by himself? None," said MacDonald.
"We are appealing to witnesses but also the parent or guardian of the child to come forward."
My guess is that this isn't about to happen anytime soon. The parents are likely completely oblivious to their demon spawns behaviour and haven't noticed any of the warning signs of a sociopathic nature, which, given this brazen attack should have been obvious to anyone with more sense than a retarded rodent.
It's likely the "my kid is wonderful and would never do something like that" syndrome that's kept them oblivious to the reality of what they're raising.