Over the past several years, Arizona policymakers have debated a number of immigration-related crime control policies. These discussions have ranged from arguments over the wisdom of granting local law enforcement agencies the authority to arrest and prosecute illegal aliens, to enacting legislation that sanctions employers for hiring illegal aliens. The perception that illegal aliens are responsible for a disproportionate amount of crime and violence in the state is at the root of many of these policy discussions. This report examines the connection between illegal aliens and crime in Maricopa County, Arizona, using data from the Arizona Arrestee Reporting Information Network.