In the late 1980s and 1990s, many state legislatures radically altered the way that their laws treated children accused of crimes. Responding to what was perceived of as an epidemic of juvenile violence, academics and policymakers began to think of child criminals as a "new breed" of incorrigible "superpredators." States responded by making it easier for prosecutors to try and sentence juveniles as adults, even making it mandatory in some circumstances.
Yet in the past decade, the Supreme Court handed down four opinions that limit the states' ability to treat children as adults in the justice system. Roper v. Simmons banned the death penalty for children under eighteen, overruling Stanford v. Kentucky. Graham v. Florida prohibited life without parole ("LWOP") sentences for children under eighteen convicted of non-homicide crimes. J.D.B. v. North Carolina held that a child's age properly factors into the "reasonable person" analysis in determining whether a police officer must give a Miranda warning. And Miller v. Alabama "combined" Roper and Graham to prohibit mandatory LWOP sentences for children under eighteen.