 Williams joined the University of Iowa Law faculty in 1977, where he taught criminal law, criminal procedure, and legislation.Williams was faculty scholar from 1990 to 1993.At Iowa, Williams served as Associate Dean of the Law School, from 1977 to 1993, where he oversaw admissions, financial aid, student and faculty recruitment, and student support, and he served as Associate Vice President of Academic Affairs from 1991–93.