Longitudinal data bases are indicated to be of interest for obtaining information on the incidence, type, chronicity, and patterns of criminal behavior. The advantages and disadvantages of self-report and official records of crime include underreporting, bias are discussed, followed by a presentation of the results of a survey of 17 States regarding their statewide central arrest record system and the possibility of research access. The survey sought information on the composition of each record system (types of offenders and whether the system has records on juveniles), the data available on persons in the system (the information that can be found on a typical file and how long records have been kept), reporting procedures and recordkeeping (who reports to the system, the frequency of reports, whether the system is computerized or manual, and any changes planned for the system), and access (the possibilities and avenues for access by researchers and information a researcher would need about a person to find him/her in the system). A table is provided to show ease of access to criminal registers by States for States with longitudinal projects. The States involved are Wisconsin, North Carolina, Pennsylvania, Texas, Vermont, West Virginia, Massachusetts, Michigan, Nebraska, New Jersey, New York, California, Florida, Illinois, Iowa, and Maryland. Thirteen references are listed.