.
The sharp increase in adolescent and young adult homicides in the late 1980s and early 1990s (Cook & Laub, 1998) was tied to the presumed new wave of juvenile "superpredators " (Blumstein, 1995; DiIulio, 1995a; Fox, 1996). The subsequent promotion of punitive policies rested on three assumptions: that the relative proportion of serious and violent offenders among all juvenile delinquents was growing; that juvenile offenders were becoming younger and younger; and that juveniles were committing more and more violent crimes. With hindsight, none of these assumptions has proved correct. .
Several researchers have debunked the superpredator myth and doomsday projections (Howell, 2003b; Males, 1996; Snyder & Sickmund, 2000; Zimring, 1998). A new wave of minority superpredators did not develop, nor did a general wave of juvenile violence occur. To be sure, rates of violent juvenile behavior increased in some cities in the 1980s and early 1990s, including Pittsburgh (Loeber, Farrington, Stouthamer-Loeber et al., 2008) and Denver (Huizinga, .
Weiher, Espiritu, & Esbensen, 2003). However, analyses of national self-report and victimization data showed that the claimed increase in juvenile violence was exaggerated (Howell, 2003b; Snyder & Sickmund, 2000). Even at the height of the juvenile crime increase (1993), "only about 6% of all juvenile arrests were for violent crimes and less than one-tenth of one percent of their arrests were for homicides " (McCord, Widom, & Crowell, 2001, p. 33). .
By the end of the 1990s, all states had enacted laws to make their juvenile justice systems more punitive or to ease transfer of more juveniles to the criminal justice system and adult prisons. Juvenile legal codes designated larger proportions of juveniles as serious and violent offenders and courts incarcerated more juveniles in detention centers and juvenile reformatories. States abandoned rehabilitative programs and used "Scared Straight " programs and boot camps that featured military-style regimented discipline.