Jean Proulx is Professor and Director of the School of Criminology at the University of Montreal, and Researcher at the International centre of Comparative Criminology of that university. His main research interests are personality profiles, sexual preferences, treatment issues, and recidivism risk factors among sexual murders, rapists, child molesters and incest offenders. Over the last twenty years, he has published four books and more than 100 book chapters or refereed articles, in French and English. Since 1989, he has been active, both as Researcher and Clinical Psychologist, in treatment programmes for sex offenders at the Philippe-Pinel Institute, a maximum-security psychiatric institution. Eric Beauregard is an Assistant Professor in the Department of Criminology at the University of South Florida. his PhD dissertation, completed at the School of Criminology, University of Montreal, was on the hunting patterns of serial sex offenders. Before joining USF in 2005, Dr. Beauregard worked as a clinical criminologist for Correctional Service Canada, where he was responsible for the phallometric and criminological assessment of sex offenders. He evaluated more than 1200 different sex offenders either during their admission process or before their release. He has published a number of studies on the offending process of sexual offenders, criminal profiling, and sexual preferences of sex offenders. Maurice Cusson is Professor at the School of Criminology a t the University of Montreal and Researcher at the International centre of comparative Criminology at that university. Over the last thirty years, he has written ten books and more than 50 book chapters or refereed articles, in both French and English. he has received four prizes for his books, including two from the Academie des Sciences Morales and Politiques de I'Institut de France. His main research interests are homicide, crime prevention, the rational-choice perspective in criminology, and national security. Alexandre Nicole is a clinical criminologist for the sex offender treatment programme at the Philippe-Pinel Institute of Montreal, a maximum-security psychiatric hospital. the institute id affiliated to the University of Montreal and M. Nicole also collaborates to various research projects related to sexual offending.