David P. Farrington, O.B.E., is Emeritus Professor of Psychological Criminology at Cambridge University. He has received the Stockholm Prize in Criminology and he has been President of the American Society of Criminology. His major research interest is in developmental criminology, and he is Director of the Cambridge Study in Delinquent Development, which is a prospective longitudinal survey of over 400 London males from age 8 to age 61. In addition to 837 published journal articles and book chapters on criminological and psychological topics, he has published 114 books, monographs and government publications, and 161 shorter publications (total = 1,112).

Harrie Jonkman studied sociology and educational studies and worked in the field of youth development and education. He works at the Verwey-Jonker Institute, a social research institute in the Netherlands. His work focuses on the social and cognitive development of children and young people, social determinants and prevention of health, developmental and behavioral problems. He was national project leader of the Community that Care strategy in the Netherlands, and supported this also in other countries. He supported prevention work in different countries, and worked in steering committees of educational institutes. At the Verwey-Jonker Institute he is involved in experiments and evaluations of social programs, longitudinal studies, and international comparative studies.

Frederick Groeger-Roth studied Sociology, Psychology and Political Sciences in Bielefeld and Berlin. He has researched on youth violence in deprived urban areas and worked for NGO’s on regional and national levels in the area of urban development. In 2009 he joined the Crime Prevention Council of Lower Saxony (CPC), located in the Ministry of Justice of Lower Saxony. He has headed the first Communities That Care pilot study in Germany, and is at present senior advisor for the CPC unit on community-based prevention. He was appointed to the expert advisory board of the German Forum for Crime Prevention and of the National Centre for Crime Prevention in Germany.