This project is intended to increase our understanding of ways to deter criminal action. It is a systematic study of the effects of neighborhood structure on the interaction between police and criminals, the proper level of aggregation necessary to delineate this interaction, and the lag time that occurs between criminal responsiveness to police sanctions and police responses to criminal behavior patterns. In this collaborative project, Drs. Kohfeld and Sprague investigate the mutual interaction between police and criminals by means of a measurement procedure that accounts for the differential time pattern of response. The uniquely rich and detailed data set they develop for carrying out these analyses is drawn from the St. Louis Metropolitan Police Department. The data set spans the time period 1970 through 1982 and is characterized by a very fine time structure-- the unit for crime occurrence is hours and the unit for arrests is days--and a very fine geographic structure--the place of each crime and each arrest is identified by X-Y coordinates and can be located as to census blocks, blockgroups, and tracts. Drs. Kohfeld and Sprague utilize an innovative geo-based software program for graphic display and analysis to aid them in their examination of criminal and police interactions under varying demographic conditions. By modelling both the offender and police reactions to one another at the incident level, the project has the potential to make a major advance in our knowledge of deterrence processes, which is central to understanding the social control and enforcement functions of law. Modelling this action-reaction process within social contexts will explain why the criminal justice system works better or differently in some places than in others and why crime is exhibited or can be deterred more effectively in some sites.
