Volume 23 includes articles by Daniel Nagin on deterrence; James Alan Fox and Jack Levin on serial and mass murder; Stephen J. Morse on "New Excuse" defenses; Christian Pfeiffer on youth violence in Western Europe; Roxanne Lieb, Vernon Quinsey, and Lucy Berliner on sexual psychopath laws; Rolf Loeber and Marc Le Blanc on the development of juvenile offending; and Michael Tonry on intermediate sanctions in sentencing guidelines.