Changing Course: Keeping Kids Out of Gangs
by Nancy Ritter, Thomas R. Simon and Reshma R. Mahendra
A new book offers evidence-based principles that can halt the cascading impact of gangs on youth, families, neighborhoods and society at large.
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The gang problem in the United States has remained stubbornly persistent over the past decade. Here are the facts:
- One in three local law enforcement agencies in 2010 reported youth gang problems in their jurisdiction.
- In a 2010 national survey, 45 percent of high school students and 35 percent of middle-schoolers said that there were gangs — or students who considered themselves part of a gang — in their school.
- Nearly one in 12 youth said they belonged to a gang at some point during their teenage years.
Public health and public safety workers who respond to gang problems know that after-the-fact responses are not sufficient. An emergency department doctor who treats gang-related gunshot wounds and a law enforcement officer who must tell a mother that her son has been killed in a drive-by shooting are both likely to stress the need for prevention — and the complementary roles that public health and law enforcement must play — in stopping violence before it starts.
But how can we prevent gang-joining, especially during a time of limited national, state, tribal and local budgets? To help meet the challenge, the Centers for Disease Control and Prevention (CDC) and the National Institute of Justice (NIJ) engaged some of the nation's top criminal justice and public health researchers to explore what the evidence shows. The result of that effort is the book Changing Course: Preventing Gang Membership and its companion executive summary, which are available in print, Web and e-book formats.
See "What's in the book?"
The Consequences of Gang Membership
The consequences of gangs — and the burdens placed on the law enforcement and health systems in our communities — are significant. Homicide is the second-leading cause of death for American adolescents and young adults: an average of 13 deaths every day among 15- to 24-year-olds. However, the number of violent deaths tells only part of the story. More than 700,000 young people are treated in emergency departments in the U.S. for assault-related injuries every year.
Although kids in gangs are far more likely than kids not involved in gangs to be both victims and perpetrators of violence, the risks go far beyond crime and violence. Gang-involved youth are more likely to engage in substance abuse and high-risk sexual behavior and to experience a wide range of potentially long-term health and social consequences, including school dropout, teen parenthood, family problems and unstable employment.
Local, state and federal budgets — in public health, criminal justice, education and community services — currently address the aftermath of gang-joining. But because the large majority of youth who join a gang do so at a very early age (between the ages of 11 and 15 ), early prevention is key.
Fortunately, we know that many early-prevention programs are effective and provide taxpayers with significantly more benefits than costs. For example, Nobel Prize-winning economist James Heckman has written about the economic benefits of targeting high-risk children before they start kindergarten. Steve Aos and his colleagues at the Washington State Institute for Public Policy have done cost-benefit analyses of prevention programs that show significant effects on a range of outcomes, including crime, educational attainment, substance abuse, child abuse and neglect, teen pregnancy, and public assistance. Many programs have substantial returns that far exceed the costs.
Therefore, in our partnership to publish Changing Course, NIJ and CDC focus on the early prevention of gang-joining, which has the potential for enormous savings for communities in terms of medical, law enforcement, incarceration and lost productivity costs — not to mention reductions in fear, increases in school security, the enhancement of property values and greater community cohesion.
How Big Is the Problem?
In the first chapter of Changing Course, James C. ("Buddy") Howell discusses the magnitude of the problem and why preventing kids from joining gangs is so important. Howell is a senior research associate at the National Gang Center who has been performing research on gangs for more than 30 years.
"At the individual level," he says, "youths who join a gang develop an increased propensity for violence, and, in turn, their likelihood of violent victimization increases. In addition, their favorable life-course outcomes are significantly reduced."
Howell discusses how gang involvement encourages more active participation in delinquency, drug use, drug trafficking and violence — all of which, in turn, may result in arrest, conviction and incarceration. Gang involvement also tends to bring disorder to the life course in a cumulative pattern of negative outcomes, including school dropout, teen parenthood and unstable employment.
With respect to community decline and costs, Howell reports that large cities have seen consistently high or increasing levels of gang-related homicides in recent years. He also discusses other impacts on communities, including loss of property value and neighborhood businesses and tax revenue, weakened informal social control mechanisms, and the exodus of families from gang-ridden neighborhoods.
According to one estimate, by Fight Crime: Invest in Kids, crime costs Americans an estimated $655 billion each year. And highly respected researchers have determined that, over the course of a lifetime, a high-rate criminal offender can impose some $4.2-7.2 million in costs on society. But, Howell notes, the costs are relatively low during the early years of a chronic offender's life (defined as six or more law enforcement contacts through age 26): about $3,000 at age 10. This, he argues, demonstrates the cost-benefit of early-prevention efforts that focus on youth in high-risk settings before problem behaviors develop.
The Attractions of Gangs
In a Changing Course chapter on the attractions of gangs, Carl S. Taylor and Pamela R. Smith discuss what the evidence shows about factors that, for some kids, outweigh the potentially life-destroying consequences of joining a gang. Taylor, a professor at Michigan State University, has worked with communities on the issues of youth violence, gangs and youth development for 40 years. Smith manages the female study for the Michigan Gang Research Project. They discuss several factors that have been shown to attract some youth to gangs, including:
Economics: For many young people who feel disconnected from the American dream, the economic opportunities of gang membership offer an acceptable alternative to a low-wage job in the legitimate-employment arena.
Relationships: Youth who feel marginalized, rejected or ignored — in the family, school or church — may join a gang to fill a need for support. Some youth join a gang for a sense of belonging, viewing the gang as a substitute or auxiliary family. For some, the appeal is that a friend or family member is already in the gang.
Protection: Although there is incontrovertible evidence that kids in a gang are more likely to be exposed to violence than kids who do not belong to a gang, this does not resonate with many young people who believe that joining a gang will protect them from violence in school or the community. Also, girls who experience physical or sexual abuse at home may believe that being in a gang offers protection.
Status: Gangs can be seen as a way to increase status among peers, a way to get respect, freedom and independence — self-empowerment factors that may be missing from some kids' lives.
Outlaw culture: Many youth — not only those at risk for gang membership — rebel against traditional societal values. During the cognitive-development stage of adolescence, being a part of an "outlaw culture" can, for some kids, be compelling.
Understanding the Role of Child Development
The promise of prevention is that most youth — even those most at risk, living in the most distressed urban communities — do not join a gang. The question, therefore, is: Why do some?
"A 13-year-old does not wake up one day and decide out of the blue to join a gang," say Nancy G. Guerra, Carly B. Dierkhising and Pedro R. Payne in Changing Course. "The decision is a consequence of a particular life environment, behavior and way of thinking that leads a child to adopt the gang lifestyle later on."
Guerra is a professor of clinical/developmental psychology at the University of Delaware and also serves as the editor of Journal of Research on Adolescence. Dierkhising, a doctoral student in developmental psychology at the University of California, Riverside, works for the National Center for Child Traumatic Stress. Payne manages a community-based nonprofit organization at Loma Linda University Medical Center in California.
Guerra and her colleagues argue that every decision we make is influenced by contexts that develop over time, and joining a gang is no different. In describing the individual and family factors in early childhood (ages 0-5) and during the elementary school years (ages 6-12), the authors note that joining a gang should be understood as part of a life course that begins when a child is born (or before). Important risk factors for children ages 0-5 include hypervigilance to threat, cognitive impairments, insecure attachment to a caregiver, and early aggressive behavior. For 6- to 12-year-olds, important risk factors include poor school performance and parental monitoring, deficits in social information-processing skills, antisocial beliefs, and negative relationships with peers, including being rejected and victimized by peers.
"We know, for example, that children are at risk for joining a gang from an early age if they are hypersensitive to threat because they regularly see shootings in the neighborhood, have fallen behind in school because they can't read, or live in neighborhoods where gangs and 'easy money' seem to go hand-in-hand," Guerra and her co-authors say.
There are protective factors, however, that can help youth who are growing up in high-risk communities; these include higher levels of social-emotional competence, academic success, secure attachment and effective parenting. The key is identifying at-risk youth and providing them with age-appropriate prevention strategies, such as those that improve family functioning and connections with schools, facilitate involvement with socially appropriate peers, and reduce bullying and victimization. Such programs can help these youth avoid a cascade of problems, including gang-joining, delinquency and violence.
The Role of Public Health
Gang membership has traditionally been viewed from a public safety, rather than a public health, perspective. In Changing Course, however, three public health experts argue that looking at the issue solely through the public safety lens fails to leverage the extensive expertise of our nation's public health professionals, who understand the impact on the health of an individual gang member and on the health of a community.
Tamara M. Haegerich, a senior health scientist at CDC's National Center for Injury Prevention and Control, has been researching youth-violence prevention for more than 10 years. Along with co-authors James A. Mercy, who oversees global violence prevention activities at CDC's Division of Violence Prevention, and Billie P. Weiss, an epidemiologist who has worked in injury and violence prevention for more than 25 years, Haegerich describes the public health approach to violence prevention. This four-step approach is based on a cross-disciplinary principle that puts everybody — those who work in medical and mental health, criminal justice, education and social services — at the table:
- Describe and monitor the problem.
- Identify the risk and protective factors.
- Develop and evaluate prevention strategies.
- Ensure widespread implementation.
Although the public health model is ideal for developing programs to help prevent kids from joining gangs, it does not come without challenges. One is that, in many respects, the idea of "prevention" is not understood or highly valued by our society.
"Policymakers and the public are strongly invested in programs and strategies that focus on punishment and that supposedly yield immediate results," Haegerich and her colleagues say. "Preventing gang violence through reductions in gang membership will require a long-term investment in research, program development and evaluation."
Public health can contribute to the development of definitions, data elements and data systems that can help the nation understand the magnitude of gang-joining and violence. Indeed, the public health approach to monitoring trends, researching risk and protective factors, evaluating interventions, and supporting the dissemination and implementation of evidence-based strategies is an important complement to law enforcement.
Haegerich and her co-authors call for fundamental operational changes in agencies and systems — as well as for the coordination of funding streams — to facilitate collaboration across sectors, generate sufficient resources to monitor gang membership, and implement and evaluate prevention strategies.
The Role of Law Enforcement
In Changing Course, Scott H. Decker says that to prevent kids from joining gangs we must move beyond "Hook 'em and book 'em." Police officers, he says, must enhance their traditional role as crime fighters by collaborating with public health, school, community and other public- and private-sector partners on primary, front-end prevention strategies.
A professor at Arizona State University who has been conducting research on gangs and gang members for more than two decades, Decker argues that the mandate for law enforcement to play a key role in gang membership prevention is clear.
"The police have a vital role in preventing youth from joining a gang in the first place," he says. "In fact, they have a true mandate with respect to efforts to prevent gang-joining: It is, quite simply, a part of their job to serve and protect."
Law enforcement can play a crucial role in a community's effort to prevent kids from joining gangs by gathering better knowledge of where gang problems exist and who is vulnerable to membership. Decker writes that, in this regard, patrol is important, and because officers are already doing this, it doesn't cost more money. Law enforcement leadership should emphasize, reinforce and reward these prevention aspects of patrolling, Decker argues.
Decker also notes that working in collaboration with other groups to prevent gang-joining increases police legitimacy and credibility, particularly in at-risk communities and among at-risk youth.
"Police legitimacy can be increased through partnerships with community groups and agencies that are trying to reduce the attraction of gangs; when police play a more active, visible role in gang-membership-prevention activities, it builds trust and improves community efficacy," he writes.
The Role of Schools
Gary D. Gottfredson, a professor at the University of Maryland, College Park, who has studied school safety issues for more than three decades, describes the need to increase the ability — and the willingness — of schools to accurately assess gang problems, implement prevention strategies, and address the fear in schools that contributes to the risk for gang-joining. Indeed, Gottfredson argues, providing a safe environment to ensure that students are not fearful may be the single most important thing that schools can do to prevent gang-joining.
"Communities must prevent gang problems and provide safe school environments not only to protect students and improve their educational outcomes but also to forestall a cycle in which school disorder and community disorganization perpetuate each other," he says.
Arguing that many principals in schools with gang problems do not recognize or admit a problem, Gottfredson points to a large study of secondary schools that found that only one-fifth of the principals in schools with gang problems (defined as more than 15 percent of students reporting they belonged to a gang) said their school had a problem.
Gottfredson says that despite their potential to reduce the risk for problem behavior and violence in the general population when implemented well, school-based programs are unlikely to reach youth who are at greatest risk of gang-joining because many have dropped out or are not fully engaged in school. In places with staggering dropout rates, such as Baltimore (41 percent), Albuquerque (49 percent) and Philadelphia (61 percent), it is unrealistic, he says, to expect to reach those youth who are most at risk with school-based programs.
"Much of the dropout occurs in the ninth grade, which means that youth at risk of dropout — who are typically poor school attendees while they remain enrolled — have little chance of exposure to programs in high school," he writes.
Finally, in Changing Course, Gottfredson discusses the importance of conducting a careful needs assessment before a school-based gang-prevention program is implemented. Assessments of gang risks, as well as the usefulness of current prevention activities, are necessary to guide future action, he says. Therefore, systematic self-report surveys regarding gang-involvement and victimization should be used to supplement existing data collection — such as school- or principal-reported incident or suspension rates — which are insufficient for developing a true picture of gang problems in schools. Schools can use this information to make decisions about which risk factors for gang-joining, including substance abuse, delinquency and violence, are most prevalent, choose programs that are known to reduce those risks, and then fully implement those programs.
The Role of Communities
Because of the heavy emphasis on school-based programs, communities have largely been overlooked as a major player in targeting kids who are at risk of joining a gang, says Jorja Leap in Changing Course. Too often, programs in the classroom are not connected to what is going on in the streets.
This disconnect can be exacerbated by a feeling in the community that a "solution" is being imposed on them from the outside — but this paradigm must change, argues Leap, an anthropologist and professor at the University of California, Los Angeles, who has more than 30 years of research experience focused on violence, culture and identity.
In her discussion on the role of communities in preventing gang-joining, Leap says that in today's economic reality — where budget cuts have reduced or entirely eliminated youth-development programs — community partnerships must step up to the plate. Emphasizing the need for comprehensive approaches that enhance "core activities" such as tutoring, mentoring, life-skills training, case management, parental involvement, connection with schools, supervised recreational activities and community mobilization, Leap outlines several key strategies, including:
- Avoid reinventing the wheel by building from programs that already exist.
- Develop strategic plans.
- Identify real and imagined boundaries.
- Make community participation a priority and maximize partnerships.
- Use training and technical assistance to expand organizational capacity.
- Ensure sustainability.
Leap discusses how communities can conduct a needs assessment, choose the right partners, and eliminate bureaucratic obstacles. The hard reality is that many community-based gang-membership prevention programs depend on a single or a small number of funding sources, she says. Because sustaining effective programs requires a funding stream, building partnerships can be crucial.
The Role of Families
Deborah Gorman-Smith and colleagues Andrea Kampfner and Kimberly Bromann Cassel discuss how early-prevention strategies can increase the protective role of families in preventing gang-joining. A professor at the University of Chicago, School of Social Service Administration, Gorman-Smith has been working in the area of youth violence prevention for 20 years. Co-author Bromann Cassel works for the Coalition for Evidence-Based Policy, and co-author Kampfner is a research associate at the Chicago Center for Youth Violence Prevention at University of Chicago, Chapin Hall.
We know, for example, that aggressive and antisocial behavior during childhood is a risk factor for crime, violence and gang involvement later in life. In general, the earlier the onset of such behavior, they note in Changing Course, the greater the severity. The age of onset, in turn, tends to be related to family functioning; serious disruptions in parenting and family functioning are related to earlier onset of delinquent behavior, which is generally more severe and dangerous than when criminal activity begins later in adolescence.
However, effective parenting and strong family functioning — with warm affective bonds, high monitoring and consistent discipline — protect against a variety of antisocial and problem behaviors, such as involvement with delinquent peers and subsequent likelihood of gang membership and violence.
"Particularly for families living in high-risk neighborhoods, programs that help to build networks of social support and foster family-community ties can provide an additional protective factor to support healthy development and prevent youth involvement in gang and other types of violence," Gorman-Smith and her co-authors say. In Changing Course, they also discuss how practitioners, policymakers and prevention scientists need to coordinate efforts for scaling up and disseminating evidence-based, family-focused programs.
Preventing Girls From Joining Gangs
Until recently, girls in gangs were often "invisible," says Meda Chesney-Lind. One reason for this is that girls enter gangs — and exit from gang activity — at younger ages than boys.
In Changing Course, Chesney-Lind, a University of Hawaii professor who has worked for years on the issue of girls in the criminal justice system, discusses families that are unable to support female adolescent development and provide basic safety. This — in conjunction with dangerous neighborhoods, possible sexual and other abuse, and poor-quality schools — paints a daunting picture for girls who are at risk of joining a gang.
Girls in gangs are far more likely than their non-gang peers to have been sexually assaulted, generally by a family member. In one study, researchers found that 62 percent of female gang members had been sexually abused or assaulted, and three-fourths said they had been physically abused.
Although girls join gangs for many of the same reasons as boys, girls are more likely to be seeking safety and security that they cannot find in a troubled or abusive home. Some girls join a gang in search of a surrogate family; others turn to a gang as a solution to family violence, believing that the gang may equip them to emotionally or physically fight back.
The reality, however, is that a gang is not a good place for protection. Girls may be raped during a gang initiation. Also, the link between post-traumatic stress disorder (PTSD) and drug use are more pronounced in girls than in boys; one study has shown that 40 percent of substance-abusing girls were experiencing PTSD compared with 12 percent of boys.
Chesney-Lind argues that preventing gang-joining should focus on helping girls stay in school and avoid substance abuse and abusive boyfriends, and give them the skills to delay early sexual activity and parenthood.
"Such work will be challenging, however, given years of inattention to girls' programming and the consequent lack of robust, gender-informed program models," she says. "We urgently need strategies to help the girls who are at the greatest risk for gang-joining, particularly those who may turn to a gang for 'protection' or a sense of belonging."
The Role of Race and Ethnicity
"The role of race and ethnicity in gang membership is becoming increasingly complicated, and it is important to understand that the term 'gang membership' is not code for race or ethnicity," say Adrienne Freng and Terrance J. Taylor in Changing Course. Freng, an associate professor in the Department of Criminal Justice at the University of Wyoming, and Taylor, an assistant professor at the University of Missouri-St. Louis, explore the complex role that race and ethnicity can play in gang membership. For example, do we need race- or ethnic-specific programming to help prevent gang-joining? Do we need more targeted programs that focus on specific risk factors for different racial and ethnic groups? Or is general gang-prevention programming — which includes some racial and ethnic-sensitive elements — sufficient?
Freng and Taylor point out that there is surprisingly little research to answer these questions. Noting some recent evidence that racial-/ethnic-specific gang-prevention programming may not be necessary, the authors suggest that general prevention programming — which includes race- and ethnic-sensitive elements — may be helpful.
"To know whether race- and ethnic-specific programming would be more successful than general gang-prevention programming, it is important that current prevention programs be better evaluated to determine whether particular impacts based on race or ethnicity exist," they say.
For now, however, Freng and Taylor argue that gang-prevention strategies should focus on "common denominators" that cut across racial and ethnic lines, such as poverty and immigration, social isolation and discrimination, drug use, limited educational opportunities, and low parental monitoring.
Evaluation: Prepare to Prove Success
In a Changing Course chapter on the importance of evaluation, Finn-Aage Esbensen and Kristy N. Matsuda say it is not a surprise that policymakers, practitioners and researchers have different mindsets when it comes to solving gang problems. But, they say, it is crucial that their thinking converge when it comes to determining whether a solution does (or does not) work.
Everyone — from federal and state policymakers to local school board members, and from health departments to police departments — needs to be able to answer the question: "How do we know if we are preventing gang membership?" Esbensen, a professor at the University of Missouri-St. Louis who has conducted research in youth violence and gangs for more than three decades, and his co-author Matsuda, an assistant research professor at the University of Missouri-St. Louis, argue that anecdotal success stories do not justify creating a new program or continuing the investment in an ongoing one. Decisions should be made using the best available evidence. Therefore, it is crucial that decision-makers understand the key principles of process, outcome and cost-effectiveness evaluations. And a formal evaluation of a strategy, initiative or program that is designed to prevent gang-joining is the only way to measure outcomes and to understand what works and why it works.
"It is important that policymakers and practitioners understand the components of the most rigorous evaluations and, most important, be able to articulate to their constituents the real-world occurrences that sometimes make an outcome evaluation difficult to execute," Esbensen and Matsuda say.
They explore the two basic types of evaluation: outcome and process. They also discuss two strategies — cost-benefit analysis and cost-effectiveness analysis — for comparing the cost of a gang-membership prevention program to the cost to society of a criminal offender.
Conclusion: An Invitation
The impacts of gang membership — and the burden it places on our health, law enforcement, corrections, social and education systems — are significant. But there is reason for optimism. By preventing youth from joining gangs in the first place, we significantly improve their chances for a safe and productive life.
In the conclusion of Changing Course: Preventing Gang Membership, NIJ and CDC extend an invitation to policymakers and practitioners to engage in a new way of thinking about the intersection of public health and public safety and leveraging resources. Indeed, the need to think more broadly about gang-joining is one of the reasons CDC and NIJ brought together diverse perspectives from public health and law enforcement and from researchers and practitioners.
Faced with the current economic realities, prevention is the best way to halt the cascading impact of gangs on our kids, families, neighborhoods and society at large. By working together to focus on the prevention of gang membership, rather than solely caring for the victims of gang violence and arresting gang-involved youth, we can change the course of the future for our kids.
NIJ Journal No. 273, posted December 2013
About the Authors
Nancy Ritter is a writer and editor with NIJ. Thomas R. Simon is a deputy associate director for science and Reshma R. Mahendra is a public health advisor with the Division of Violence Prevention at the Centers for Disease Control and Prevention.
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For More Information
 Egley, Arlen, Jr., and James C. Howell, Highlights of the 2010 National Youth Gang Survey (pdf, 4 pages), OJJDP Juvenile Justice Fact Sheet, Washington, D.C.: U.S. Department of Justice, Office of Juvenile Justice and Delinquency Prevention, April 2012, NCJ 237542.
 National Center on Addiction and Substance Abuse at Columbia University, National Survey of American Attitudes on Substance Abuse XV: Teens and Parents (pdf, 75 pages), New York: National Center on Addiction and Substance Abuse at Columbia University, 2010.
 Snyder, Howard N. and Melissa Sickmund, Juvenile Offenders and Victims: 2006 National Report, Washington, DC: U.S. Department of Justice, Office of Justice Programs, Office of Juvenile Justice and Delinquency Prevention, 2006.
 Centers for Disease Control and Prevention, Web-Based Injury Statistics Query and Reporting System (WISQARS), Centers for Disease Control and Prevention, National Center for Injury Prevention and Control, 2009.
 Thornberry, Terence P., Marvin D. Krohn, Alan J. Lizotte, Carolyn A. Smith, and Kimberly Tobin, Gangs and Delinquency in Developmental Perspective), New York: Cambridge University Press, 2003; Peterson, Dana, Terrance J. Taylor, and Finn-Aage Esbensen, "Gang Membership and Violent Victimization," Justice Quarterly 21 (4) (December 2004): 793-815.
 Krohn, Marvin D., Jeffrey T. Ward, Terence P. Thornberry, Alan J. Lizotte, and Rebekah Chu, "The Cascading Effects of Adolescent Gang Involvement Across the Life Course," Criminology 49 (4) (November 2011): 991-1028.
 Howell, James C., Gang Prevention: An Overview of Research and Programs (pdf, 24 pages), OJJDP Juvenile Justice Bulletin, Washington, D.C.: U.S. Department of Justice, Office of Juvenile Delinquency and Prevention, December 2010, NCJ 231116.
 Heckman, James J., "Skill Formation and the Economics of Investing in Disadvantaged Children," Science 312 (June 2006): 1900-1902.
 For more information, see the Washington State Institute for Public Policy's website.
 Krohn, Marvin D., and Terence P. Thornberry, "Longitudinal Perspectives on Adolescent Street Gangs," in ed. A.K. Liberman, The Long View of Crime: A Synthesis of Longitudinal Research, New York: Springer, 2008: 128-160; Howell, Megan Q., and William Lassiter, Prevalence of Gang-Involved Youth in NC (pdf, 7 pages), Special Issue Fact Sheet, Raleigh, N.C.: North Carolina Department of Juvenile Justice and Delinquency Prevention, December 2011.
 Howell, James C., Gangs in America's Communities, Thousand Oaks, Calif.: Sage Publications, 2012.
 Howell, James C., Arlen Egley, Jr., George E. Tita, and Elizabeth Griffiths, "U.S. Gang Problem Trends and Seriousness, 1996-2009" (pdf, 23 pages), National Gang Center Bulletin, No. 6, Tallahassee, Fla.: Institute for Intergovernmental Research, National Gang Center, May 2011.
 Decker, Scott H., and David C. Pyrooz, "Gang Violence Worldwide: Context, Culture, and Country" (pdf, 28 pages), in Small Arms Survey 2010: Gangs, Groups, and Guns, Geneva, Switzerland: Small Arms Survey, 2010: 129-155.
 Christeson, William, and Sanford Newman, Caught in the Crossfire: Arresting Gang Violence by Investing in Kids (pdf, 32 pages), Washington, D.C.: Fight Crime: Invest in Kids, 2004.
 Cohen, Mark A., and Alex R. Piquero, "New Evidence on the Monetary Value of Saving a High Risk Youth," Journal of Quantitative Criminology 25 (2009): 25-49; Cohen, Mark A., Alex R. Piquero, and Wesley G. Jennings, "Estimating the Costs of Bad Outcomes for At-Risk Youth and the Benefits of Early Childhood Interventions to Reduce Them," Criminal Justice Policy Review 21 (4) (2010): 391-434.
 Cohen and Piquero, "New Evidence on the Monetary Value of Saving a High Risk Youth."
 Padilla, Felix M., The Gang as an American Enterprise, New Brunswick, N.J.: Rutgers University Press, 1992; Brown, William B., "The Fight for Survival: African-American Gang Members and Their Families in a Segregated Society," Juvenile and Family Court Journal 49 (2) (May 1998): 1-14; Cureton, Steven R., "Introducing Hoover: I'll Ride for You, Gangsta'," in ed. R.C. Huff, Gangs in America III, Thousand Oaks, Calif.: Sage Publications, 2002: 83-100.
 Wiener, Valerie. Winning the War Against Youth Gangs: A Guide for Teens, Families, and Communities, Westport, Conn.: Greenwood Press, 1999.
 Ibid.; Shelden, Randall G., Sharon K. Tracy, and William B. Brown, Youth Gangs in American Society, Belmont, Calif.: Wadsworth, 2004; Howell, James C., Youth Gangs: An Overview (pdf, 20 pages), OJJDP Juvenile Justice Bulletin, Washington, D.C.: U.S. Department of Justice, Office of Juvenile Justice and Delinquency Prevention, August 1998, NCJ 167249.
 Peterson, Taylor, and Esbensen, "Gang Membership and Violent Victimization"; Wiener, Winning the War Against Youth Gangs: A Guide for Teens, Families, and Communities.
 Miller, Jody, "The Girls in the Gang: What We've Learned From Two Decades of Research," in ed. R.C. Huff, Gangs in America III, Thousand Oaks, Calif.: Sage Publications, 2002: 175-198.
 Cicchetti, Dante, Fred A. Rogosch, Megan R. Gunnar, and Sheree L. Toth, "The Differential Impacts of Early Physical and Sexual Abuse and Internalizing Problems on Daytime Cortisol Rhythm in School-Aged Children," Child Development 81 (1) (January/February 2010): 252-269; Decker, Scott H., "Collective and Normative Features of Gang Violence," Justice Quarterly 13 (2) (1996): 243-264; Fearon, R. Pasco, Marian J. Bakermans-Kranenburg, Marinus H. Van Ijzendoorn, Anne-Marie Lapsley, and Glenn I. Roisman, "The Significance of Insecure Attachment and Disorganization in the Development of Children's Externalizing Behavior: A Meta-Analytic Study," Child Development 81 (2) (March/April 2010): 435-456; Bowlby, John, Attachment and Loss, Volume 2: Separation: Anxiety and Anger, New York: Basic Books, 1973; Hill, Karl G., Christina Lui, and J. David Hawkins, Early Precursors of Gang Membership: A Study of Seattle Youth (pdf, 6 pages), OJJDP Juvenile Justice Bulletin, Washington, D.C.: U.S. Department of Justice, Office of Juvenile Justice and Delinquency, December 2001, NCJ 190106.
 Hill, Karl G., James C. Howell, J. David Hawkins, and Sara R. Battin-Pearson, "Childhood Risk Factors for Adolescent Gang Membership: Results From the Seattle Social Development Project," Journal of Research in Crime and Delinquency 36 (3) (August 1999): 300-322; Huesmann, L. Rowell, and Nancy G. Guerra, "Normative Beliefs and the Development of Aggressive Behavior," Journal of Personality and Social Psychology 72 (2) (1997): 1-12; Fraser, Mark W., "Aggressive Behavior in Childhood and Early Adolescence: An Ecological-Developmental Perspective on Youth Violence," Social Work 41 (4) (July 1996): 347-361; Robertson, Angela A., Connie Baird-Thomas, and Judith A. Stein, "Child Victimization and Parental Monitoring as Mediators of Youth Problem Behaviors," Criminal Justice and Behavior 35 (6) (June 2008): 755-771.
 Gottfredson, Gary D., and Denise C. Gottfredson, Gang Problems and Gang Programs in a National Sample of Schools, Ellicott City, Md.: Gottfredson Associates, 2001.
 Swanson, Christopher B., Cities in Crisis 2009: Closing the Graduation Gap. Bethesda, Md.: Editorial Projects in Education Research Center, 2009.
 Steinberg, Laurence, "Familial Factors in Delinquency: A Developmental Perspective," Journal of Adolescent Research 2 (3) (1987): 255-268.
 Miller, Jody, "Young Women in Street Gangs: Risk Factors, Delinquency, and Victimization Risk," in eds. W.L. Reed, and S.H. Decker, Responding to Gangs: Evaluation and Research (pdf, 320 pages), Washington, D.C.: U.S. Department of Justice, 2002: 67-105; Esbensen, Finn-Aage, and David Huizinga, "Gangs, Drugs, and Delinquency in a Survey of Urban Youth," Criminology 31 (4) (November 1993): 565-589.
 Joe, Karen A., and Meda Chesney-Lind, "'Just Every Mother's Angel': An Analysis of Gender and Ethnic Variations in Youth Gang Membership," Gender & Society 9 (4) (August 1995): 408-431.
 Joe Laidler, Karen A., and Geoffrey Hunt, "Violence and Social Organization in Female Gangs," Social Justice 24 (4) (Winter 1998): 148-169.
 Esbensen, Finn-Aage, Elizabeth Piper Deschenes, and L. Thomas Winfree, Jr., "Differences Between Gang Girls and Gang Boys: Results from a Multisite Survey," Youth & Society 31 (1) (September 1999): 27-53; Esbensen, Finn-Aage, Dana Peterson, Terrance J. Taylor, and Adrienne Freng, Youth Violence: Sex and Race Differences in Offending, Victimization, and Gang Membership, Philadelphia, Pa.: Temple University Press, 2010.
 Deyken, Eva Y., and Stephen L. Buka, "Prevalence and Risk Factors for Posttraumatic Stress Disorder Among Chemically Dependent Adolescents," American Journal of Psychiatry 154 (6) (June 1997): 752-757.
 Esbensen, Peterson, Taylor, and Freng, Youth Violence: Sex and Race Differences in Offending, Victimization, and Gang Membership.