In 1994, twelve years after his stint as mayor, Hanna joined the Caddo Parish government as the director of building and grounds and later served as the director of operations and as assistant administrator. In June 1998, he was named Caddo Parish administrator, comparable to county judge in most other states. He was the administrator until his retirement in 2006. In this capacity, he helped to resolved the disputed boundary with neighboring Bossier Parish, which impacted revenues collected from boats docked in the Red River. He brought the three major governmental headquarters together to the downtown Government Plaza building, helped to establish the Northwest Louisiana Veterans Cemetery, built a Chimp Haven in Shreveport, and devised an emergency cell phone program for the handicapped and elderly.