Abigail A. Fagan is an Associate Professor in the Department of Sociology, Criminology & Law at the University of Florida. J. David Hawkins is the Emeritus Endowed Professor of Prevention in the School of Social Work at the University of Washington. Richard F. Catalano is a Professor in the School of Social Work at the University of Washington. David P. Farrington is Emeritus Professor of Psychological Criminology at the Institute of Criminology at Cambridge University.