His research focuses on various aspects of juvenile delinquency and young adult offending, with an emphasis on the role of peer associations and self-control. His recent publications have appeared in journals such as Criminology, the Journal of Quantitative Criminology, Crime and Delinquency, Criminal Justice and Behavior, and the Journal of Youth and Adolescence. He also recently co-authored the book Self-Control and Crime Over the Life Course published by Sage Publications.