Cover Page

Wiley Handbooks in Criminology and Criminal Justice

Series Editor: Charles F. Wellford, University of Maryland College Park.

The handbooks in this series will be comprehensive, academic reference works on leading topics in criminology and criminal justice.

The Handbook of Law and Society
Edited by Austin Sarat and Patricia Ewick

The Handbook of Juvenile Delinquency and Juvenile Justice
Edited by Marvin D. Krohn and Jodi Lane

The Handbook of Gangs
Edited by Scott H. Decker and David C. Pyrooz

The Handbook of Deviance
Edited by Erich Goode

The Handbook of Criminological Theory
Edited by Alex R. Piquero

The Handbook of Drugs and Society
Edited by Henry H. Brownstein

The Handbook of Gangs


Edited by

Scott H. Decker and David C. Pyrooz









Notes on Contributors

Adam Baird, PhD, is Assistant Professor of International Peace Studies and Urban Governance at the UN University for Peace. He studies gangs, youth, gender and masculinity, and violence prevention and reduction in Central America and the Caribbean.

Julie Barrows, PhD, is Adjunct Professor of Sociology at the University of Minnesota. Her dissertation examined the formation, network structure, and effectiveness of gang task forces. In addition to conducting gang research, she has worked in the criminal justice system for many years, and currently serves as a federal agent.

Kathryn Benier is a PhD Candidate in the School of Social Science at the University of Queensland, and a Research Assistant at the Institute for Social Science Research. Her dissertation focuses on the community factors influencing the incidence of hate crime in Australia.

Beth Bjerregaard, PhD, is a Professor and Chair in the Department of Criminal Justice & Criminology at the University of North Carolina at Charlotte. She received her PhD in Criminal Justice from the State University of New York at Albany. Her research interests include capital punishment, gang membership, and gang delinquency.

Brenda J. Bond, PhD, is an Associate Professor of Public Service at Suffolk University. Her work focuses on the management and performance of police organizations as well as cross-agency collaboration. She has examined these issues in a book co-edited with Erika Gebo, Looking Beyond Suppression: Community Strategies to Reduce Gang Violence (2012), and has recently published a paper on crime outcomes associated with effective group work in policing.

Anthony A. Braga, PhD, is the Don M. Gottfredson Professor of Evidence-Based Criminology in the School of Criminal Justice at Rutgers University and a Senior Research Fellow in the Program in Criminal Justice Policy and Management at Harvard University. His research involves addressing illegal access to firearms, reducing gang violence, and controlling crime hot spots.

Krystal S. Campos is a recent graduate of Suffolk University’s Dual Master’s Degree Program: Crime and Justice Studies and Mental Health Counseling. She has been a research assistant on studies focusing on youths who are considered high-risk for gang and criminal involvement and the effects of youths living in high-risk environments.

Arna L. Carlock is a PhD Candidate in the School of Criminal Justice at the University at Albany and an analyst for the Rochester Youth Development Study. Her primary research interests include anticipated early death and gang violence, stability, and desistance.

Dena C. Carson, PhD, is an Assistant Professor in the School of Public and Environmental Affairs at Indiana University Purdue University Indianapolis. Her general research interests include youth violence, victimization, gangs, and delinquent peer groups. Her recent publications have appeared in Youth & Society, Journal of Criminal Justice, and Youth Violence & Juvenile Justice.

Megan E. Collins is a PhD Student in the Department of Criminology and Criminal Justice at the University of Maryland. Her research interests include policing practices, gang violence, and criminal justice policy.

G. David Curry, PhD, is Professor Emeritus in the Department of Criminology and Criminal Justice at the University of Missouri-St. Louis. He earned his PhD in sociology from the University of Chicago in 1976. His research addresses issues dealing with gangs and delinquency, military service, hate crime, and domestic violence.

Scott H. Decker, PhD, is Foundation Professor in the School of Criminology and Criminal Justice at Arizona State University. His main research interests are in the areas of gangs, violence, criminal justice policy, and the offender’s perspective. He is a Fellow in the American Society of Criminology and the Academy of Criminal Justice Sciences.

James A. Densley, PhD, is Assistant Professor of Criminal Justice at Metropolitan State University, Minnesota. He earned his doctorate in sociology from the University of Oxford. Densley’s teaching and research interests include street gangs, criminal networks, violence, and theoretical criminology. He is the author of How Gangs Work: An Ethnography of Youth Violence (2013).

Beidi Dong is a doctoral candidate in the Department of Sociology and Criminology & Law at the University of Florida. His research interests include developmental and life-course criminology, youth gangs and violence, crime and place as well as juvenile delinquency and justice in a comparative sense.

Finn-Aage Esbensen, PhD, is the E. Desmond Lee Professor of Youth Crime and Violence and also serves as the Chair of the Department of Criminology and Criminal Justice at the University of Missouri-St. Louis.

Mark S. Fleisher, PhD, a cultural and linguistic anthropologist, is a Research Professor at the Jack, Joseph and Morton Mandel School of Applied Social Sciences, Case Western Reserve University. He has written Warehousing Violence (1989), Beggars and Thieves (1995), Crime and Employment (2004), Dead End Kids (1998), The Myth of Prison Rape (2009), and Few Escape (2015).

Adrienne Freng, PhD, is currently a Full Professor in the Department of Criminal Justice at the University of Wyoming. Her research interests include juvenile delinquency, gangs, and race and crime issues, including specifically how they relate to American Indian populations. She has written and co-authored numerous articles based on these topics, as well as co-authored Youth Violence: Sex and Race Differences in Offending, Victimization, and Gang Membership (2010).

Shytierra Gaston, MS, is a doctoral candidate in the Department of Criminology and Criminal Justice at the University of Missouri-St. Louis and a National Science Foundation graduate research fellow. Her research areas focus on corrections, prisoner reentry, families of offenders, and race, crime, and justice.

Erika Gebo, PhD, is an Associate Professor of Sociology at Suffolk University. Her areas of interest include youth violence and the implementation and evaluation of crime policies and programs. She recently co-edited the book Looking Beyond Suppression: Community Strategies to Reduce Gang Violence (2012) with Brenda J. Bond.

Chris L. Gibson, PhD, is a Research Foundation Professor and Associate Professor of Criminology at the University of Florida. He also holds affiliate appointments in the College of Medicine, Institute for Child Health Policy and the College of Law’s Criminal Justice Center. He recently co-edited with Marvin D. Krohn the book Handbook of Life-Course Criminology: Emerging Trends and Directions for Future Research (2013).

Howard Giles, PhD, is Professor of Communication at the University of California, Santa Barbara. He is founding Editor of the Journal of Language and Social Psychology and the Journal of Asian Pacific Communication and was past President of the International Communication Association and the International Association of Language and Social Psychology.

Liran Goldman is a recent PhD graduate from the Department of Behavioral and Organizational Sciences at Claremont Graduate University in Los Angeles. She is a recipient of a Department of Homeland Security Fellowship as well as a START (Study of Terrorism and Responses to Terrorism) Research Award.

Angela Higginson, PhD, is a Lecturer in Criminology at the School of Social Science at the University of Queensland. Her research evaluates policing and community crime control interventions. Recent work includes systematic reviews of the predictors and prevention of youth gangs in low- and middle-income countries.

Michael A. Hogg, PhD, is Professor of Social Psychology at Claremont Graduate University in Los Angeles. He is founding Editor of Group Processes and Intergroup Relations, a former Associate Editor of the Journal of Experimental Social Psychology, and past President of the Society of Experimental Social Psychology.

James C. Howell, PhD, is a Senior Research Associate with the National Gang Center, in Tallahassee, FL, where he has worked for 19 years. Dr. Howell enjoys gang research and is active in helping states and localities address gang and juvenile delinquency problems using evidenced-based services and programs.

Beth M. Huebner, PhD, is an Associate Professor at the University of Missouri-St. Louis. She received her PhD from the Michigan State University in Criminal Justice. Her current research interests include prisoner reentry, criminal justice decision making, and public policy. Her current research explores the efficacy of current sex offender policy and the long-term patterns of recidivism among serious, violent offenders.

C. Ronald Huff, PhD, is Professor Emeritus at both the University of California, Irvine, and the Ohio State University. His current research focuses on gangs, wrongful convictions of innocent persons, and public policy. He is a Fellow and past President of the American Society of Criminology.

Lorine A. Hughes, PhD, is Associate Professor in the School of Criminology and Criminal Justice at the University of Nebraska at Omaha. The last of Professor Short’s graduate students, she has spent the past few years digitizing and reanalyzing Short and Strodtbeck’s data using modern methods. Resulting publications (with Short) appear in Criminology and the Journal of Quantitative Criminology.

Marvin D. Krohn, PhD, is at the University of Florida. He is interested in life course approaches. His work on the Rochester Youth Development Study has led to numerous research articles and a co-authored book, Gangs and Delinquency in Developmental Perspective, which was the American Society of Criminology’s recipient of the 2003 Hindelang Award for Outstanding Scholarship. He was recently named a Fellow of the ASC.

Alan J. Lizotte is Dean and Professor of Criminal Justice at the University at Albany and a co-principal investigator of the Rochester Youth Development Study. His research interests include guns and gun control, correlates and causes of delinquency over the life course, and policy health issues for clients of the criminal justice system.

Cheryl L. Maxson, PhD, is a Professor in the Department of Criminology, Law and Society at the University of California’s Irvine campus. Her research addresses street gangs, status offenders, youth violence, juvenile justice legislation, and community treatment of juvenile offenders.

Jean M. McGloin, PhD, is an Associate Professor in the Department of Criminology and Criminal Justice at the University of Maryland. Her research interests include peer influence, co-offending, and offending specialization. Her work has been published in Criminology, the Journal of Research in Crime and Delinquency, and the Journal of Quantitative Criminology.

Meghan M. Mitchell, MS, is a Doctoral Student at Sam Houston State University. Her interests include the intersection of social justice issues (race, class, gender) and crime, along with gangs and school-based delinquency.

Richard K. Moule, Jr., MS, is a Doctoral Student in the School of Criminology and Criminal Justice at Arizona State University. His research interests include gangs and deviant networks, developmental/life-course criminology, and the intersection of technology and criminological theory. He is the archivist for the Walter B. Miller Library.

Vanessa R. Panfil, PhD, is a Post-Doctoral Associate in the School of Criminal Justice at Rutgers University. She studies how intersections of gender and sexuality shape individuals’ experiences with gangs, crime, victimization, and the criminal and juvenile justice systems. She co-edited, with Dana Peterson, Handbook of LGBT Communities, Crime, and Justice (2014).

Andrew V. Papachristos, PhD, is an Associate Professor of Sociology, Public Health, and Law at Yale University. His research applies the growing field of social network analysis to understanding patterns of crime victimization in US cities. His writing has appeared in Foreign Policy, The American Journal of Sociology, The Annals of the American Academy of Social and Political Science, The American Journal of Public Health, The Journal of Urban Health, and Criminology & Public Policy, among other outlets.

Dana Peterson, PhD, is an Associate Professor in the School of Criminal Justice at the University at Albany. She studies youth gangs, violence, and how sex and gender structure these. Publications include Youth Violence: Sex and Race Differences in Offending, Victimization, and Gang Membership (2010, with Esbensen, Taylor, and Freng), and Handbook of LGBT Communities, Crime, and Justice (2014, with Panfil).

David C. Pyrooz, PhD, is an Assistant Professor of Sociology at the University of Colorado Boulder. He studies gangs and deviant networks, violence, and developmental and life-course criminology. He is the co-author with G. David Curry and Scott Decker of Confronting Gangs: Crime and Community (3rd edition, 2013) and the recipient of the 2015 Academy New Scholar Award from the Academy of Criminal Justice Sciences.

Rob Ralphs, PhD, is a Senior Lecturer in Criminology at the Manchester Metropolitan University, United Kingdom. His current research focuses on UK gang policy, including his recent co-authored article, “Used and Abused: The Problematic Usage of Gang Terminology in the United Kingdom and Its Implications for Ethnic Minority Youth,” in the British Journal of Criminology.

Dennis Rodgers, PhD, is Professor of Urban Social and Political Research at the University of Glasgow. A social anthropologist by training, he works on issues relating to urban development, conflict, and violence in Nicaragua, Argentina, and India. His most recent publication is the volume Global Gangs: Street Violence across the World co-edited with Jennifer Hazen (2014).

Michael Sierra-Arevalo, MA, is a Doctoral Student in the Department of Sociology at Yale University, and an affiliate fellow at the Institution for Social and Policy Studies (ISPS). His research focuses on gangs, the police, urban violence, and the causes and effects of legal cynicism.

Hannah Smithson, PhD, is a Reader in Criminology in the Department of Sociology and Criminology at Manchester Metropolitan University, United Kingdom. Her current research focuses on UK gang policy, including her recent co-authored article, “Used and Abused: The Problematic Usage of Gang Terminology in the United Kingdom and Its Implications for Ethnic Minority Youth,” in the British Journal of Criminology.

Frank van Gemert, PhD, is Assistant Professor at the Department of Criminal Law and Criminology at VU University Amsterdam. As a qualitative researcher, he prefers to collect data as an ethnographer and, more recently, as a biographer. His work is on gangs, drug dealers, homicide, squatters and, more generally, cultural criminology.

J. Michael Vecchio, PhD, is an Assistant Professor in the Department of Criminal Justice and Criminology at Loyola University Chicago. His research interests include youth violence and victimization, youth gangs, and responses to victimization. His most recent published work appeared in Deviant Behavior.

Frank M. Weerman, PhD, is a senior researcher at the Netherlands Institute for the Study of Crime and Law Enforcement (NSCR). His publications focus on the explanation of juvenile delinquency, on co-offending and youth gangs, and on quantitative analyses of social networks, delinquent peers, and peer-related activities.

L. Thomas Winfree, Jr. PhD, is Visiting Professor in Arizona State University’s School of Criminology and Criminal Justice. He has co-authored multiple editions of five textbooks, including Understanding Crime: Essentials of Criminological Theory (3rd edition, 2009); he has also co-edited two anthologies, including Social Learning Theories of Crime (2012). Winfree is co-author of dozens of theory-based articles.

DaJung (DJ) Woo (M.A., Kansas State University) is a PhD student in the Communication Department at the University of California, Santa Barbara. Her research projects examine the processes and dynamics in which individuals become socialized and assimilated into groups, organizations, and occupational roles through communication.


Scott H. Decker and David C. Pyrooz

The Handbook of Gangs is a comprehensive volume that presents the current state of knowledge about gangs. Each of the chapters is written by a leading expert in the world on their chosen topic and stands alone as an insightful review of what is known about that topic. But taken together the chapters provide us with a broad understanding of the foundation for gang research, the theories and methods used to study gang behaviors and processes, the many forms of gangs, the correlates of gangs and gang membership, gang prevention and intervention programs, and gang experts. Indeed, we believe that one of the strengths of the book is the series of interrelationships among the chapters. While the topics of each chapter are different, they are related through themes, problems, theories, and methods.

The goal of this volume is to provide a definitive reference for professionals working in the field of gang prevention or suppression, researchers, and students. What we know about gangs has become interdisciplinary and internationalized in the course of the past 20 years, and our book reflects both of those trends. We believe that this volume pulls together the most contemporary reviews on the key topics in the understanding of gangs and the responses to gangs. To accomplish this, we have engaged the best scholars in their area, many of whom have chosen to work with an emerging scholar. Each chapter provides a critical review of what is known about the topic, as well as the insights of the authors about the topic. In this way the book will be grounded in the current knowledge about the specific topics, but also provides new material that reflects the knowledge of the leading minds in the field. While there is a strong orientation toward sociological criminology in the book, we believe that the chapters reflect a broad approach in both method and theory, continuing to expand the boundaries of gang research.

The book is organized into seven sections:

  1. Laying the Foundation for Understanding Gangs (Chapters 2–4)
  2. Theories of Gangs (Chapters 5–10)
  3. Gang Correlates (Chapters 11–12)
  4. Gang Processes (Chapters 13–16)
  5. Responding to Gangs (Chapters 17–21)
  6. Pioneers in Gang Research (Chapters 22–25)
  7. Gangs in International Context (Chapters 26–29)

There are many unique features to the book and we use this introduction to walk the reader through those features. One aspect of the book that we are particularly proud of is the personal touch in many of the chapters. We encouraged the authors to give us insights into their personal knowledge about the research and researchers in their topic area. We think this makes the chapters more interesting to the reader. This is an especially important feature of this book as many of the authors are intimately involved with the production of knowledge in the area of their chapter, know other individuals working on contemporary research in the area, and have a strong appreciation for the history of work in that area. For example, Andrew Papachristos is among the leading network theorists and methodologists in the social sciences. He has teamed with Michael Sierra-Arevalo to produce an outstanding chapter (9) on the use of network analysis and theory with gangs which integrates network theory with their ongoing network analysis. Finn Aage-Esbensen wrote a chapter (20) on the Gang Resistance Education and Training (G.R.E.A.T.) project that is insightful for what it tells us both about G.R.E.A.T. from an evaluator’s perspective as well as about evaluation methods. Similarly, Anthony Braga ranks among the very best police scholars in the world, and has written an excellent chapter (17) on the role of the police in responding to gangs, particularly focused deterrence approaches. We believe that the other chapters reflect a comparable level of prominence among the authors. Indeed, the names of many of these authors are synonymous with the topics of their chapters.

Over the past two decades, there has been a virtual explosion of gang research. Indeed, the third chapter of this book, written by David Pyrooz and Meghan Mitchell, traces the history of gang research and documents this explosion in great detail, what they term the transition from “little” to “big” gang research. A key theme in the history of gang research is the definition of a gang, a theme that David Curry revisits in his chapter (2) nearly two decades after his work on the logic of defining gangs and measuring gang activities. In their chapter (4) on documenting gang activity, Ronald Huff and Julie Barrows show us not only why the definition and measurement of gangs is so important, but also the essential features of how gang intelligence is gathered and recorded. Indeed, the explosion of research on gangs has occurred in tandem to responses to gangs, which rely on the very records carefully described by Huff and Barrows.

Research on gangs has grown in theoretical sophistication as well in methodological rigor. Theoretical developments have followed Short’s tripartite focus on macro, micro, and individual theories and levels of explanation. Each of these levels of explanation is represented in this volume. This includes new perspectives such as social psychological approaches to the study of gangs (DaJung Woo, Howard Giles, Michael Hogg, and Liran Goldman, chapter 8), emerging perspectives such as the growing attention to gang membership in developmental and life course perspective (Beidi Dong, Chris Gibson, and Marvin Krohn, chapter 5), and longstanding perspectives such as social learning theory (Thomas Winfree and Adrienne Freng, chapter 7). Further, the correlates of gangs and gang membership are documented in chapter 10, on violence and synergy between gangs and guns (Arna Carlock and Alan Lizotte), chapter 11, on the connections between gangs, drugs, and culture (Mark Fleisher,), and chapter 12, that rethinks gender and gangs (Vanessa Panfil and Dana Peterson). At the macro-level Andrew Papachristos and Lorine Hughes (chapter 6) provide a chapter on neighborhoods and gangs that is not anchored to any single theoretical perspective, which is often contentious, instead viewing gangs as “independent variables” and “dependent variables” as causes and consequences of neighborhood social organization and problems.

Perhaps most importantly, the book also pays explicit attention to explanations of gang-related processes and behaviors. This remains the least studied, yet perhaps most important of the remaining items on the gang research agenda. Chapters 13 and 14 tackle the important processes of how people enter and exit from gangs. James Densley presents readers with a theory of joining gangs that is rooted in a signaling perspective, something that offers great value to gang research. Dena Carson and Michael Vecchio, alternatively, review the current state of the evidence on disengaging from gangs, a burgeoning area of gang research. True to Short’s calls for micro-level gang research, Jean McGloin and Megan Collins expertly outline in chapter 15 the micro-level intra- and inter-gang processes theorized to elevate levels of crime and violence among gangs and gang members. These processes are believed to make gangs qualitatively different, which is why in chapter 16 we (the editors) ask: what are the structural, organizational, and social features that gangs uniquely possess compared to other criminal and extremist groups?

Units of government (cities, states, and the federal government) have worked to develop responses to gangs. While some of these responses have emphasized suppression to the exclusion of other approaches, there is a growing emphasis on prevention and intervention programs. For example, the Centers for Disease Control and the National Institute of Justice have collaborated to produce a volume titled Changing Course, that reviews the primary areas of responding to gangs from an integrated public health and criminal justice perspective. Many of its chapters explicitly acknowledge the efforts to control the spread of gangs and the harm that gang membership causes through increased criminal involvement. This handbook captures these trends in several chapters, most notably Shytierra Gaston and Beth Huebner’s chapter on gangs and corrections (18), Beth Bjerregaard’s chapter on gang legislation (19), and Erika Gebo, Brenda Bond, and Krystal Campos’s chapter (21) on the Office of Juvenile Justice and Delinquency Prevention (OJJDP) Comprehensive Strategy.

The spread of gangs in the United States and the worldwide growth in the use of the Internet has meant that gangs have “gone global.” American-style youth gangs can now be found in a growing number of countries around the world. While there are some core similarities across these gangs, in many cases they are quite distinctive, reflecting religious, cultural, historical, and institutional differences of the countries. Frank van Gemert and Frank Weerman (chapter 27) examine trends, patterns, and correlates of contemporary European gangs. Their chapter is nicely complemented by Rob Ralphs and Hannah Smithson’s review (chapter 28) of gang intervention strategies in Europe. While much gang research has crossed the Atlantic to Europe, Dennis Rodgers and Adam Baird (chapter 26) identify a growing body of research in Latin American countries and Angela Higginson and Kathryn Benier (chapter 29) close the book with a review of what is known about gangs in Asia, Africa, and Australia. These chapters are explicitly comparative and contemporary.

But we believe that the most unique contribution found in the book comes in the four chapters that examine the work of four individual gang researchers who have made contributions to this literature since the middle classic era of gang research. The four individuals whose contributions are highlighted in separate chapters advancing the understanding of gangs are: Malcolm Klein, Irving Spergel, James F. Short Jr., and Walter Miller. Each of these individuals is responsible for developing a pillar of the foundation of gang research. We term these the “legacy” chapters. Each chapter examining their involvement in gang research has elements of autobiography, historiography, and philosophy of science, in addition to a review of their work. These chapters were written by individuals who have worked with or have been intimately involved with the work of the four pioneers. Lorine Hughes, who wrote the chapter about James F. Short, Jr., was one of his doctoral students and has worked with him and the data from his Chicago project. Cheryl Maxson wrote the chapter about Malcolm Klein. Cheryl and “Mac” have worked together for over 20 years and no one knows Mac’s work better than Cheryl. James C. Howell worked closely with the late Irving Spergel to develop the “Spergel Model” which became the basis for nearly $100 million of federal gang intervention efforts. Richard Moule wrote the chapter about Walter Miller. It is fair to say no one has read more of Walter’s work than Richard and while they never met, he understands Miller’s work better than anyone in the field today. We hope you like reading them as much as we have.

It is appropriate to ask what the next steps are for gang research and policy. What are the questions that need to be answered that have not been resolved or not even been asked? We see four broad areas that are ripe for the attention of young scholars.

First, it is important to address the gaps in our current knowledge about gangs. This includes a number of salient topics such as the role of technology in gang behavior and the spread of gang behavior. The digital empowerment assumption holds that the Internet and social media offer key advantages to gangs and other criminal networks, yet it might also prove to be a detriment. What is needed is an understanding of if and how these new technologies influence gang behavior. Also, so much of what is known about gangs is derived from a criminological perspective, yet the very mechanisms leading to criminal behavior are not exclusive to this behavior but general to a variety of non-criminal consequences as well. Therefore it is necessary to learn about the implications – negative and positive – of gangs for other socializing institutions.

Second, we know all too little about group process in gangs despite Short’s work from nearly 50 years ago exhorting us to better understand group process. This concern is closely tied to the level of measurement brought to understand gangs. This is an issue that is far more than an arcane devotion to method and measurement; indeed it is at the core of what we need to know about gangs. Short urges us to consider whether we are studying and responding to individuals (gang members), groups (gangs), or structural aspects of society (class, neighborhood variables, or the like). Despite his influential work on this topic in the 1960s and 1980s, there is still inadequate attention to these issues.

Third, we lack an understanding of how gangs compare to other groups involved in crime. The growth of interest in terrorist and extremist groups, organized crime groups, drug smugglers, and money launderers (to name but a few) is illustrative of this interest. Do these groups share common organizational, structural, or group process variables? Are these groups wholly distinct and different from each other? Are there overlaps between these groups that draw our attention to a common understanding and shared responses? Do individuals belong to multiple gangs or transition from one form of crime organization (such as gangs) to another (such as organized crime or terror groups)? We have a long way to go in pursuing these questions and much of the progress will likely be made outside of gang research.

Fourth, and in a related point, we need to import models and methods from other disciplines. Scholars and policymakers working toward a better understanding and response to organized crime have made valuable use of trial transcripts as sources of data, pointing the way toward more innovative sources of information about the topics we wish to study. Those who study terrorists and terrorism use data from social media such as Twitter, Facebook, and email to better understand and respond to such groups. The world of gang scholarship has been slow to utilize such data and many have been resistant to the use of new forms of data. This is indeed ironic since most gang members are at the peak ages for the use of social media, the late teens.

We brought these authors and their chapters together to produce a comprehensive volume of knowledge about gangs and gang members. The chapters are written by the leading authorities in the world on their given topic. It is our goal that this book will be used by those who seek to understand gangs and to craft changes to improve the lives of gang members and those affected by their behavior. We hope you find that the book accomplishes these goals.

Finally, it is important that we acknowledge those working “behind the scenes” who made this book come together. We thank Chantal Fahmy, Rick Moule, Matthias Woeckener, and Jun Wu, each of whom spent an extraordinary amount of time and care poring over the chapters. The good folks at Wiley Blackwell, notably Linsay Bourgeous, Haze Humbert, Julia Kirk, Allison Kostka, Breanna Locke, and Julia Teweles, were excellent to work with and ensured the success of this project across each stage of the process. Our colleagues at Arizona State University and Sam Houston State University, including Gaylene Armstrong, Cassia Spohn, and Vince Webb, among others, are deserving of recognition for supporting this project over the last three years. Most importantly, we are grateful to our families. Thank you to JoAnn, Sara, Laura, and Elizabeth. And thank you to Natty, Cyrus, and Adalyn. A final thank you is in order to each of the contributors for participating in this project.

Sadly, our friend and colleague Dave Curry passed away on April 26, 2015. We are very proud to include chapter 2, his last published work, in this volume. Dave was a pivotal figure in the study of gangs and juvenile justice. His work was always motivated by and focused on improving the lives of young people. We miss you, man.