Christopher D. Webster, PhD, is Professor and Chair of the Department of Psychology at Simon Fraser University in Burnaby, British Columbia. Formerly Head of Psychology and Head of the Impulsivity Programme at the Clarke Institute of Psychiatry in Toronto and Professor of Psychiatry, Psychology and Criminology at the University of Toronto, Dr. Webster has published extensively about assessing risk of violence.

Margaret A. Jackson, PhD, a psychologist by training, is Professor and Director of the School of Criminology at Simon Fraser University. Formerly a Research Scientist at the Metropolitan Toronto Forensic Service (METFORS), Dr. Jackson has completed several studies on the way dangerousness is perceived by clinicians and members of the judiciary, and has written and edited several books on clinical criminology.