Sections I and II of this essay provide overviews of major conceptions of law and prevention that portray typologies of each. The third section summarizes current knowledge of the preventive effects of criminal penalties and critiques the likely effectiveness of various "legal" approaches to "crime prevention." The focus is on how law addresses the traditional common law crimes of violence and property. The essay concludes that the enactment and implementation of criminal laws is but one of the measures that governments can use to prevent crime; criminal laws and sanctions are not likely by themselves to have substantial effects on crime rates. Governments should create and support specialized agencies that have prevention as their major focus. Enormous amounts of knowledge have been compiled in the past decade about the effects of situational and developmental prevention; if this knowledge is to grow and be more broadly applied, some specialized agencies must be given responsibility for doing so. Governments must modify their preoccupations with criminal codes and sanctions as the sole or primary mechanisms for preventing crime. 44 references