The Army's Criminal Investigative Task Force (CITF) used a commercially available tool and reliable data about detainees such as where they were captured, who they associated with, and other details about their relationships and behaviors to construct a chart of all the detainees. Using a system called Proximity–a system developed by the University of Massachusetts-the CTTF was able to calculate a probability that a given detainee was a terrorist or just a person in the wrong place at the wrong time.