Using National Incident-Based Reporting System data to assess agency differences in clearance rates: a recommendation for law enforcement

The National Incident-Based Reporting System (NIBRS) disaggregates crime clearances into crimes cleared by arrest and crimes cleared by exceptional means. This feature is an improvement to the Summary Reporting System and allows law enforcement agencies to perform cross-jurisdiction comparisons of their clearance practices and investigative performances. This study uses sexual assault clearance rates to demonstrate a method of cross-jurisdiction comparison, which can be used to improve agency practices. Findings show much variability in sexual assault clearance rates across agencies, but most of this variation is explained by agency use of clearance by exceptional means. Further, no single agency characteristic examined here explained variability in exceptional clearance rates. Finally, there was additional agency variation in the offense type used to clear a sexual assault by arrest. The article concludes with a discussion of the importance of NIBRS for advancing law enforcement research and practice and the need for greater attention to data quality in NIBRS.