GeoShadow: Location Based Offender Monitoring

 In 2004, the Oklahoma Department of Corrections (ODOC) received legislative approval to implement a global positioning satellite (GPS) offender monitoring program designed to provide oversight for the structured release and successful reentry of offenders incarcerated for non-violent as well as addressing the financial shortfalls and physical capacity issues confronting the state’s criminal justice system.  The program allows eligible offenders an opportunity to complete the final segment of their incarcerated sentence in the community.   Offenders in this program are subject to continuous monitoring through a GPS device. The geo spatial point data is either transmitted through cellular towers in urban areas or through telephone landlines in rural areas of the state.  The program participants are supervised by PPOs who monitor the offender’s geospatial movements daily. 

In order to ensure that Oklahoma’s current GPS program is highly effective and efficient and offered to all persons eligible for participation, ODOC officials have joined in a partnership between the University of Oklahoma, Center for Spatial Analysis (OU CSA),  and the National Institute of Justice (NIJ), Office of Science & Technology, Operational Technologies Division ( to evaluate the performance of their current GPS monitoring system and develop a cutting-edge and technologically advanced GIS toolkit for the spatiotemporal analysis of movement patterns of individual GPS participants and group behaviors. The OU CSA research team will use the current GPS program adopted by the (ODOC) as an example to evaluate the functions and utilities of the current GPS systems available, the nature of end users interaction with the current GPS system, and their current unmeet analytical needs in order to improve utilization of the system, and user analysis capabilities.  Overall, the ability to better assess inmate program eligibility, identify problematic behavior patterns as they unfold, and improve the usability and functionality of corrections-based GPS monitoring systems should reduce the number of unsuccessful program terminations through the utilization of early intervention strategies with GPS program participants.

 Research products will include case studies with GPS data from ODOC, detailed evaluation report of end user issues with the current GPS monitoring system and unmet needs, a detailed How-to report for analyzing current systems with a crosswalk between the capabilities of the tools developed in the tool kit and identified user needs, a toolkit, source codes, user manual, and scheduled project reports.   While the ODOC system is used as a test case, the GIS toolkit and manuals are expected to be broadly adaptable for other states and delivered as freeware. With the understanding that many GPS programs have been developed on various software platforms, the toolkits will be designed on common data structures (such as shapefile or ASCII data formats) of paths in GPS coordinates. Common data formats will serve to as bridges between the toolkit and a GPS program system. The toolkits will be used to export the GPS program, analyze the data, and display the analytical outcomes in a form that is tailored to the needs and work environment of Probation and Parole Officers.