During his tenure at the Naval Criminal Investigative Service, Gelles served as a lead for “Project Slammer,” a U.S. government study on convicted American spies. He has supported the Office of the National Counterintelligence Executive in a number of espionage and other insider investigations; directly participating in more than ten debriefs of convicted spies. As a Director at Deloitte Consulting LLP, he has continued to focus on solutions around mitigating insider threats; including innovative solutions that integrate behavior and access within the virtual world of business, in both the private and public sectors.