An analysis of criminal deterrence research concludes that evidence for a substantial deterrent effect is much firmer than it was two decades ago, although four types of gaps in knowledge on the links between policy actions and behavior make it difficult to assess the effectiveness of policy options for deterring crime. An overview of policies toward sexual predators concludes that effective policies should include long sentences for high-risk and dangerous offenders, the use of actuarial assessments of risk to make determinations about dangerousness, and a focus on the prevention of violent and sexual reoffending. A review of developmental criminology emphasizes the importance of finding variables that determine or mediate the variation of behavior with age. An analysis of intermediate sanctions in sentencing guidelines notes that concepts such as parsimony and mechanisms such as categorical exceptions have promise for scaling punishment severity to crime seriousness and for saving money. A paper on juvenile crime and violence in Europe reports an increase in youth violence in the United States and 10 European countries, as well as variations in the mix of law enforcement and prevention efforts undertaken in different countries. An examination of issues and arguments concerning excusing concludes that the current system of criminal blame and punishment is coherent, is fair in principle, and can accommodate the claims for new excuses. A discussion of serial and mass murderers notes that both offenders are typically white males in their late 20s or 30s, although their targets and methods often differ. Figures, tables, and reference lists