Understanding Arrest Data in the National Incident-Based Reporting System (NIBRS)

• In Event: Measuring Police Performance and Impacts

Abstract

The use of national and state crime statistics to drive data-driven policy and decision making has increased in recent years. The Bureau of Justice Statistics and the FBI are working together on a project to create the National Crime Statistics Exchange (NCS-X) based on the National Incident Based Reporting System (NIBRS) to improve the use of crime statistics. NIBRS data analysis has begun to contribute substantially to knowledge, particularly in explaining arrests. However, research suggests problems with reliability of arrest data, which are not always updated to capture new case information after submission to NIBRS. This presentation will report on the reliability of NIBRS arrest data and explore factors supporting or detracting from its accuracy. Findings from a stratified random sample from NIBRS of 480 incidents of aggravated assault, simple assault, sexual assault and intimidation investigated by local police in Massachusetts from 2011 to 2013 will be presented. Each sampled law enforcement agency was approached to collect data on the sampled cases to be compared on accuracy. Additionally interviews from local agencies represented in the sample were conducted to explore factors that enable or interfere with accurate data delivery, such as NIBRS instructions, definitions and training, or Records Management System.

Authors

• Alex Wagner, Fisher College

• Ted Cross, University of Illinois at Urbana–Champaign

• Daniel Bibel, Fisher College

• Ryan Koch, Fisher College