William L. Marshall has served in many roles, most recently as Director of Rockwood Psychological Services, which provided treatment and research for various types of offenders, including sexual offenders. Rockwood provided these services from 1971 until 2013 in an outpatient clinic and in several Canadian Federal penitentiaries as well as in a center for mentally disordered offenders. These programs addressed adult and juvenile sex offenders in various prison and community settings. Rockwood also provided therapist trainings in many countries. Bill has 424 publications including 18 books, one of which won the Society for Sex Therapy and Research’s “Book of the Year” award. Bill has been on the Editorial Boards of 17 international journals and was in 2003 elected a Fellow of the Royal Society of Canada for his contributions to science. In 2006, Bill was appointed an Officer of the Order of Canada in recognition of his contributions to making society safer both nationally and internationally. This is the highest honor a Canadian citizen can receive.