The United States is the only developed democracy in the world that condemns children to adult prisons and locks them up in solitary confinement. It has the highest rate of child incarceration in the world. U.S. states allow children under 14 to be tried criminally despite prohibitions in human rights law and medical evidence demonstrating these children are not capable of criminal culpability. This chapter demonstrates the numerous rights violations inflicted on children in the criminal justice system. It explains how the Supreme Court’s neglect of children’s rights is rooted in its asserted constitutional identity and contrasts it with decisions from other national and international courts. It also explains a set of cases dealing with the harshest punishments for children in which the Court tentatively embraced a human rights approach. These cases demonstrate clearly the strength of relying on human rights law. Here again interviews with experts form an important part of the analysis.