This paper describes the structure of an executive decision support system based on a data warehouse about offences and clearance rates in British Columbia. The system was developed at the Institute for Canadian Urban Research Studies at Simon Fraser University. The paper explains how the data mining and automated statistical analysis in this system can be used by criminologists for analysis of crime trends both at the jurisdiction level and province wide. Database technologies and statistical functions have been utilized in a set of programs that encapsulate the knowledge of experts. The paper explains how by performing repeated regression analysis on all Jurisdiction-crime combinations the system can discover important and significant trends at the local level and how general province-wide trends can be detected. An example of using the system to evaluate the relationship between reported crime rates and clearance rates is explained.