text: Soon as a child steps aboard a school-bus, or onto the school-grounds, the school accepts supervisory responsibility for the child, during posted hours. This is so because school is compulsory, creating the nexus.
  A child under state control, as in a foster home or juvenile detention, is fully the responsibility of the state.
  Failure of a parent to properly supervise their child, is an subjective assessment, which can be qualified in a court of law. A parent's failure to properly supervise, usually triggers child endangerment laws, more often than criminal or civil liability.
  Laws which inhibit a parent's ability to exercise full control over their child, can mitigate the parent's ultimate responsibility.
  The Judo/Christian belief is that "The parents shall not suffer for the sins of their children, nor shall the children suffer for the sins of their parents".
  It's a "can-of-worms" no matter which way you turn. Certainly not settled science.