"Over the past decade or more, virtually every state in the union has taken steps to create a juvenile justice system that is not just tough on crime but smart on crime-fair and just practices that protect communities and help all kids become responsible adults. The systems now taking shape embrace the best ideas from earlier waves of reform-society’s responsibility to its youth, the need to create safe communities-and put them in a new framework: a scientific understanding of child and adolescent development, the tools to evaluate what works and what doesn’t, and the determination to put our scarce taxpayer dollars where the evidence is" (p. 9). This report discusses how the fourth wave of reform will influence the juvenile justice system. Sections following an executive summary include: introduction; a brief history of juvenile justice-the "discovery" of childhood, enter the child savers, a second wave of reform, the third wave of backlash, the consequences, and the fourth wave; reducing incarceration and its harms; treating kids as kids, not as adults; diverting youths from the system; ensuring equal treatment and due process; balancing youth development, personal accountability, and public safety; and into the future.