Criminology lost an influential scholar with the passing of Malcolm “Mac” Klein on August 1, 2023, in Los Angeles, just short of his 93rd birthday. His legacy includes a distinguished record of scholarship, institutions he fostered, and generations of scholars he influenced.
Mac made noteworthy contributions to knowledge about patterns of delinquent offending, self-report methods of crime measurement, juvenile diversion, deinstitutionalization of status offenders, community policing, program evaluation, and cross-national comparisons of these issues. Most recognized for his scholarship on street gangs, the first of several books, Street Gangs and Street Workers (1971), derived from two gang programs he evaluated in the 1960s. Trained as a social psychologist, Mac studied group cohesiveness, leadership patterns, organization, and structure and how these processes influence individual and group behavior, including – but not limited to – crime and violence. He insisted that a science of gangs was predicated on common definitions and comparable research methods and did much to advance the field in these areas. Accordingly, he was recognized as a fellow by the American Society of Criminology, the American Psychological Association, and the American Psychological Society and was awarded the ASC’s Sutherland and Vollmer Awards as well as the Marvin Wolfgang Award for Distinguished Achievement in Criminology.
Mac was an institution-builder. He chaired the Department of Sociology at the University of Southern California for 13 years and established the Social Science Research Institute there. Together with Josine Junger-Tas, he convened the first gathering of researchers that would go on to develop the International Self Report Delinquency Study, currently in its 4th sweep. One of his proudest achievements was the formation of the Eurogang Research Program. This group of international researchers encourages the use of multi-site, multi-method research to study gang activity. Over the course of 21 workshops beginning in 1998, the group has agreed upon a consensus definition of street gangs, developed common instruments, and edited six volumes reporting original research on gangs and gang-like groups throughout the world.
In the first sentence of his 1971 book, he declares, “I’ve had it with gangs.” The two of us, and generations of gang scholars, are grateful he changed his mind. Our thoughts are with his fellow traveler and wife, Margy Gatz, daughter Laurie Klein and three grandsons. We are glad he was in our lives.