 He studied and analyzed more than 3,000 cases of threats against Federal judges and prosecutors.Calhoun felt that these threats – often made by people whose lives were directly affected by the court – were inherently different from threats to other public figures, with whom the threateners rarely had any real contact.The marshals service selected the MOSAIC method for applying Calhoun's research, and Gavin de Becker & Associates was commissioned to co-develop a new system