As the use of criminal background checking has become widespread, the quality of criminal history records, on which background checks are based, has become increasingly important. This project, which is funded by the Maryland Department of Public Safety and Correctional Services (DPSCS), examines the completeness, accuracy, and timeliness of the criminal history data stored in the Maryland criminal record registry (i.e. Criminal Justice Information System). In order to complete this task, we obtain data from each of the criminal justice system sub-systems (law enforcement, courts, and corrections) and compare it to what is stored in the registry and used in background checks.