Gangs and the Military Note 3: The Role of the West Coast in the Development of Military-Trained Gang Members
Carter F. Smith
This note reviews the current state of military-trained gang members (MTGMs) in the United States military. MTGMs, whether from Street Gangs, Outlaw Motorcycle Gangs (OMGs), or Domestic Terrorist Extremist (DTE) groups, have endangered U.S. communities since before the birth of the country. Early gang leaders acquired military training before and during the Revolutionary War, and continued their criminal activity as the population transitioned westward. The earliest MTGMs included river pirates, stealing cargo and attacking passengers along the Ohio and Mississippi Rivers, and later the street gangsters who controlled much of the criminal street business in New York, New York and some of the police and politicians of that time. Members of one DTE group started as a New York street gang, received military training and experience in Mexico during the Mexican-American War, and were released from active duty in the newly-named city of San Francisco, just before the Gold Rush of 1848. The issues of MTGMs today tend to mirror those in history, indicating that a solution to the problem is elusive, perhaps even unattainable.
Although military laws prohibit active membership, members of many street gangs, Outlaw Motorcycle Gangs (OMGs), and Domestic Terrorist Extremist (DTE) groups have or are enlisted in the U.S. military. The Army Criminal Investigation Command (CID), Air Force Office of Special Investigations (AFOSI), and Naval Criminal Investigative Service (NCIS) have identified military personnel with gang membership or affiliation in every branch. Street gang, OMG, and DTE group members with military training are military-trained gang members (MTGMs). MTGMs are not a new phenomenon and have existed as long as the United States. In each wartime era since the Revolutionary War, there have been examples of MTGMs who practiced their criminal activities in the civilian communities.
Gang members and associates may join the military to get away from the gang lifestyle and the criminal temptations associated with it. They may also join to acquire military training and access to weapons and sensitive information. A military-trained gang member (MTGM) is defined as a street gang, prison gang, OMG, or DTE group member per the applicable jurisdiction’s definition, with military training or experience, as perceived by a reasonable, typical, police officer.
Literature Related to Gang Members in the Armed Forces
At present, the literature lacks much empirical research regarding the presence of MTGMs in communities. Limited research has been conducted on MTGMs in the community. This section summarizes the early history of MTGMs on the West Coast and historical studies of MTGMs; street gang, OMG, and DTE members in the military.
A Brief History of Military-Trained Gang Members
In Boston, the early gang members had training in the colonial militia. Ebenezer MacIntosh was one such gang leader, as head of the South Enders around 1764. The South Enders were frequent winners of the annual brawl with the North Enders each year on November 5, Pope’s Day. The two groups fought over each other’s effigies of the Pope, which were burned by the winners. The South Enders gang became so bold as to loot the homes of several government officials in their protest of the Stamp Act of 1765, after which Mackintosh was known as the South Enders’ “Captain General,” a militia term used to denote supreme authority of an area or command.
Once the country was formed, militia leaders focused on defending against attacks by Indians (Native Americans). Samuel Mason was one such veteran, becoming a river pirate and preying on travelers who headed west on the Ohio River. Mason received his military training as a militia captain in the Ohio County Militia, part of the Virginia State Forces, in 1777. Mason was given command of Fort Henry, in what is now known as West Virginia. After his service he led a gang of river pirates travelling back and forth along the Ohio and Mississippi Rivers, robbing passengers of their cargo and boats. Ultimately, Mason moved his operation to the Natchez Trace, along which travelers would return to the northeast with the profits from merchandise they had taken down the river.
Some of the gangs in early New York City received military training in preparation for and during the Mexican –American War. In the mid-1800s, many were transplanted to San Francisco, CA following the war and prior to the Gold Rush. Those early MTGMs, known as the Hounds, were hired as security by local business leaders to return runaway sailors at $25 a head. Many sailors had left their ships’ crew as soon as their ships arrived at the port in San Francisco, ultimately leaving 400 cargo-laden ships abandoned as the sailors went to the gold mines. The harbor quickly filled, preventing additional ships from entering and bringing their cargo to the area. Once the Hounds got those problems under control, they renamed themselves the San Francisco Society of Regulators, and preyed on (attacking) “foreigners” (namely Mexicans, Peruvians, and Bolivians) in the newly acquired territory of California.
Prior Studies of Military-Trained Gang Members
In 1992, Knox conducted an exploratory study of a sample of convenience comprised of 91 members of an Illinois National Guard unit. An incident involving the death of a child had occurred in a large public housing complex that was known for gang violence. The shooter, a gang member, had served in the military, and public officials had suggested the possibility that the National Guard could have been called to assist in suppressing the gang problem. Survey respondents estimated gang membership in the military ranged from a low of zero to a high of 75% with a mean of 21.5%. The results of that research were summarized in Table 1.
Table 1: Estimates of the percent who were current or former gang members by branch
McMaster examined attitudes towards gangs on a military base in Arizona and found there was no significant difference regarding perceptions of the severity of the gang problem between ranks of the respondents. In the 1993 study, 63.5% of the respondents did not believe that gangs were a serious problem in their on-base or off-base neighborhoods. Few of the respondents reported direct contact with gangs, and 83.59% reported they were never a target of gang violence. Few significant differences were identified in how military personnel living on and off base responded to questions.
In 1996, in response to the racially-motivated homicides of a civilian couple by soldiers stationed at Fort Bragg, North Carolina, members of a worldwide Department of the Army task force evaluating the effects of extremist groups. After conducting over 7,000 interviews and 17,080 written surveys, the task force concluded there was minimal evidence of extremist-group activity in the Army. The survey found 3.5 percent of the participants had been approached by extremist groups and asked to take part in their activities. About 7 percent said they knew another soldier they believed was a member of an extremist group. The task force noted, though, there was more of a "security concern" with street gangs than extremists. Specifically, they reported "gang-related activities appear to be more pervasive than extremist activities as defined in Army Regulation 600-20."
The 2017 Gang and Domestic Extremist Activity Threat Assessment (GDEATA)
The annual report produced by the U.S. Army CID appears to be designed to demonstrate a broad and equally diverse problem with organized criminal MTGMs, perhaps to the point of bias. Nonetheless, in the fifteen years the report has been produced, an overwhelming number of identified MTGMs have been members of street gangs, as was noted by the 1996 task force. In the FY2012 Gang and Extremist Activity Threat Assessment (GEATA), the Department of Defense started distinguishing Street Gangs from OMGs and DTE groups in their annual reports with no explanation why, then or since. The FY 2017 CID Assessment, as many others before it, focused on identifying a “threat level,” conducted limited longitudinal analysis of the data, and connected gang involvement to security clearances. The report noted an increase in street gang investigations over the past three years, with no attempt to comment on possible contributors. No change (increase or decrease) in OMG-related investigations over the past two years was noted, with only a slight increase from the year before, with no attempt to explain the results. It was noteworthy that the ten OMG cases in 2017 amounted to about one-fourth of the thirty-eight street gang cases. The report also noted no change in the number of DTE cases investigated from the previous year. An apparent bias toward the extent of the street gang, OMG, and DTE problem in the military was also seen in the pictorial display on the cover of the report. Of the eleven photos in the collage, Street Gangs were represented three times, there were five OMG-related photos, and only two DTE photos. The relationship of one photo was not discernable.
As has been typical, most of the street gang suspects were junior enlisted (E-1 to E-4) and young (under 24). African Americans made up eighty percent of the suspects, while Caucasians comprised twenty percent. Half of the OMG suspects were African American, while under 40 percent were Caucasian and thirteen percent Hispanic. Most of the OMG suspects were noncommissioned officers (E-5 to E-9). The report noted the continued increase nationwide in African American OMG groups, as well as possible collaboration between street gang and OMG members with members of car clubs. The report also explained that Army leaders were concerned about Soldiers who joined OMGs or their support clubs because those members were typically of higher rank and more time in the military, likely to influence younger soldiers.
Surveys of West Coast Gang Investigators
The Modified Military Gang Perception Questionnaire (MMGPQ) was used to collect data from gang officers and investigators. The primary questions were designed to determine the perception of the respondents regarding the presence of MTGMs in their community. The questions were as follows:
1) Gang members in my jurisdiction are increasingly using military-type weapons or explosives.
2) Gang members in my jurisdiction use military-type equipment (body armor, night-vision, etc.).
3) Gang members in my jurisdiction use military-type tactics.
4) Gang members in my jurisdiction commit home invasions.
5) Gang members in my jurisdiction commit armed robberies.
6) There are gang members in my jurisdiction that currently serve in the military.
7) There are gang members in my jurisdiction that have served in the military in the past.
8) Military representatives advise our department when gang members are discharged.
Figure 1: Legend summarizing responses by question
In May 2014, 305 gang investigators from Washington, Oregon, Idaho, and Montana in Spokane, Washington were asked to complete the survey, and 166 of them did. That response rate provided a 95 percent confidence level and a 5.14 percent margin of error. Many respondents reported gang members in their jurisdictions were increasingly using military-type weapons or explosives (27 percent), as well as military-type equipment like body armor and night-vision devices (19 percent). Although few (14 percent) agreed that gang members were using military-type tactics, a majority (over 65 percent) reported gang members committed home invasions and armed robberies. Eighteen percent reported that there were gang members in their jurisdiction currently serving in the military, while 33 percent reported they had gang members who had previously served. Most of the respondents (79 percent) did not believe that military representatives advised their department when gang members were discharged from the military.
Gang members in the respondents’ jurisdiction represented many branches of the military, although the Army was the most often reported, followed by the Army National Guard and the Army Reserve. The Crips, 18 Street, Bloods, Gangster Disciples, and Mara Salvatrucha were the street gangs represented most by the MTGMs in survey respondents’ jurisdictions. The OMGs and DTEs represented by MTGMs were not separately recorded. The results were summarized in Table 2.
Table 2: Responses for Washington, Oregon, Idaho, Montana
In June 2014, I surveyed 97 Arizona gang investigators in Tempe, Arizona and 31 participants responded, providing a 95 percent confidence level and a 14.59 percent margin of error. Most respondents reported gang members in their jurisdictions were increasingly using military-type weapons or explosives (55 percent), as well as military-type equipment such as body armor and night-vision devices (52 percent). Although only one in three (36 percent) agreed that gang members were using military-type tactics, a majority (over 80 percent) reported gang members committed home invasions and armed robberies. Twenty-six percent reported that there were gang members in their jurisdiction currently serving, while 49 percent reported they had gang members who had previously served. Most of the respondents (61 percent) did not believe that military representatives advised their department when gang members were discharged from the military.
Gang members in the respondents’ jurisdiction represented many branches of the military, although the Army was the most often reported, followed by the Marine Corps and the Air Force. The Bloods, Crips, Gangster Disciples, Vice Lords, and Latin Kings were the street gangs represented most by the MTGMs in survey respondents’ jurisdictions. The OMGs and DTEs represented by MTGMs were not separately recorded. The results were summarized in Table 3.
Table 3: Responses for Arizona
In October 2014, I passed out the survey questionnaire to gang officers in Redwood City, California. One hundred and twenty-one participants from California completed the survey, for a 95 percent confidence level and a 6.47 percent margin of error. Most respondents reported gang members in their jurisdictions were increasingly using military-type weapons or explosives (66 percent), as well as military-type equipment like body armor, night-vision devices, and so on (56 percent). Although few (33 percent) agreed that gang members were using military-type tactics, a majority (over 84 percent) reported gang members committed home invasions and armed robberies. Many (31 percent) reported that there were gang members in their jurisdiction currently serving, while 51 percent reported they had gang members who had previously served in the military. Most of the respondents (53 percent) did not believe that military representatives advised their department when gang members were discharged from the military.
Gang members in the respondents’ jurisdiction represented many branches of the military, although the Army was the most often reported, followed by the Marine Corps and the Army Reserve. The Norteños, Sureños, and Mara Salvatrucha (MS-13) were the street gangs represented most by the MTGMs in survey respondents’ jurisdictions. Of the OMGs represented by MTGMs, the Hells Angels, Mongols, and Vagos were most reported. Sovereign citizens comprised the largest group of DTEs represented by MTGMs, followed by white supremacists and racist skinheads. Most survey respondents (51 percent) reported that fewer than 10 percent of their gang members had some form of military training, and most (32 percent) respondents reported the MTGMs in their jurisdiction received military training directly. The results were summarized in Table 4.
Table 4: Responses for California
In April 2015, the survey was presented to 305 Nevada gang officers in Las Vegas, Nevada, and 114 answered all or almost all the questions on the survey. That response rate provided a 95 percent confidence level and a 7.28 percent margin of error. Most respondents reported gang members in their jurisdictions were increasingly using military-type weapons or explosives (56.6 percent), as well as military-type equipment like body armor and night-vision devices (46.3 percent). Although several (39.6 percent) agreed that gang members were using military-type tactics, a majority (over 85 percent) reported gang members committed home invasions and armed robberies. Most (51.8 percent) reported there were gang members in their jurisdiction currently serving in the military, while 62.3 percent reported they had gang members who had previously served in the military. Almost half of the respondents (49.1 percent) did not believe that military representatives advised their department when gang members were discharged from the military.
Gang members in the respondents’ jurisdiction represented many branches of the military, although the Air Force was the most often reported, followed by the Army and the Marines. The Sureños, Bloods, and Crips were the street gangs represented most by the MTGMs in survey respondents’ jurisdictions. Of the OMCGs represented by MTGMs, the Hells Angels, Mongols, and Vagos were most reported. Sovereign citizens comprised the largest group of DTEs represented by MTGMs, followed by white supremacists and racist skinheads. Most survey respondents (67.1 percent) reported that fewer than 10 percent of their gang members had some form of military training, and most (79.7 percent) respondents reported the MTGMs in their jurisdiction received military training directly. The results were summarized in Table 5.
Table 5: Responses for Nevada
The National Gang Intelligence Center (NGIC) recently found that known or suspected gang members in over 100 responding jurisdictions had sought or obtained employment in the military or a public criminal justice field in the previous two years. Employment with the U.S. military ranked as the most common, followed by corrections. Nonetheless, many military leaders and public affairs offices refer to the relatively low numbers of identified MTGMs and suggest the problem is small, discounting not only the cancerous effect on affected military units, but the increased dangerousness to the civilian community as the MTGMs depart military service.
According to the U.S. Army’s long-stated position, gang members represent less than one percent of all military members. That number may be intended to represent an insignificant amount, but the attempt at minimization of the issue misses the mark. At any given time, the military has over 2 million service members. There were 1,333,240 active duty service members and 817,384 reservists at the start of 2017. That’s a total of 2.15 million. If less than 1/100th of them are gang members, then we only need to be concerned about 21,500 service members who could be simultaneously involved in military service and criminal gangs. While that is a relatively small number if we are considering the size of a city, it represents a sizable number of influential and dangerous individuals.
Familiar organizations which have in the range of 20,000 members, for example, include the Aryan Brotherhood, a nationwide prison gang; the membership of the International Association of Chiefs of Police (IACP); and the student body at Harvard University. To excuse the existence of gang members in the military would be to say that the military, like McDonald’s or Wal-Mart, with over a million youthful employees around the world, understandably draws a few gang members into its ranks from the gang lifestyle. Neither McDonalds nor Wal-Mart runs a background check that rivals the security clearance conducted as standard fare by the military and neither organization trusts their global employees with an issued weapon and ammunition and the authority to engage an armed enemy.
The authors of just about every report by the NGIC have observed “gang members with military training pose a unique threat to law enforcement personnel.” The threat posed to law enforcement was even more significant if MTGMs trained other gang members in weapons, tactics, discipline, and planning. Whether trained in combat arms, logistics, finance, or other military occupational specialties, the gang member with military experience should be considered more advanced and dangerous than the gang member without military experience, and the potential threat MTGMs pose to law enforcement is significant. All facets of the criminal justice system throughout the United States (police, courts, and corrections) at the local, state, and federal level have the potential to encounter MTGMs. Military experience adds a dangerous dimension to the gang member which is not seen in those without military training.
Responses to Gangs
Depending on with whom you are speaking, the list of what “works” and what doesn’t is likely to be different. Researchers Curry, Decker, and Pyrooz summarized their research by pointing out that while the response to gangs was hardly well-coordinated, it was organized into categories: 1) community organization, 2) social intervention, 3) opportunities provision, 4) suppression, and 5) organizational development and change. Suppression appeared to be the only effective category for the military, so that is the one we will spend time to evaluate. Many gang scholars claim to have the best fix for one gang problem or another. What hasn’t been discovered is a solution to either the adult gang problem or the gang member in the military problem. While there are several good strategies and treatments for the “typical” gang member, MTGMs are a select group of people who choose to add or keep a relationship in their lives that is in direct conflict with their sworn and committed primary duty—service to the country and allegiance to it against all enemies, foreign and domestic.
Sadly, I don’t think there is likely to be a real solution for the existence of gang members in the military community. I say this not because I doubt the ability of policymakers or military leaders, but because of the unique nature of the military justice system. In the civilian community, if a person commits a crime and gets caught, the criminal justice system is mobilized to correct the problem, often by running the person through the courts to the corrections system, perhaps by restricting the person’s movements to or from a specific area (using probation or injunctions, respectively), and by using an intelligence system to keep tabs on the individual. That process allows the police to get to know the various gang-involved individuals in their community and assists them in determining the best remedies for gang behavior.
The military typically has no such system, at least not for the adult gang member who is also a member of the military. In the absence of an integrated intelligence system, the Military Police have one opportunity to learn who is a gang member, and if the military system works there will be no need to do anything further. Given the relatively limited engagement that Military Police have with the community, if a person’s behavior is so bad that the police are engaged, that person is not likely to remain a member of the community. Thus, the police are severely restricted from gathering valuable intelligence on embedded and concealed gangs and gang members, and will only interact with the less advanced criminal element.
High Intensity Cognitive–Behavioral Program
In contrast to the approaches taken by the military, some prison systems are using a system of treatment designed to deter recidivism. The process is described as a high intensity cognitive–behavioral (HICB) program. The researcher focuses on communities inside the prison system. While prison is clearly not the same as the military, there are a few notable similarities, including the increase in discipline and restriction of freedoms. The basics of the HICB program include using culturally sensitive teaching and therapeutic approaches to address the offenders’ needs, providing the offenders with a supportive environment to practice and generalize the new skills; and requiring an exit strategy for the offenders. Overall recidivism is significantly reduced, and for the few who reoffend, the activity is less serious.
A version of the HICB treatment used in the military might start with acknowledged gang members seeking to join the military. Instead of simply taking their word that they have desisted from gang activity and continue to do so, the military could assign counselors to debrief the admitted gang member as he enters the military. Working with the recruit, a plan of action could be designed to help him through the stressors and triggers likely to appear during the term of his enlistment. Periodic (quarterly, perhaps leading to annual) follow-up could be scheduled, to ensure the process is effective.
Gangs as a Public Health Issue
Sanders suggested the consideration of gangs as a public health issue. He noted that gang-involved youth were at increased risk for incarceration, as well as negative health and social outcomes. Community responses to gangs might improve if they were public health problems, Sanders suggested, as those programs were more defensive and focus on prevention. A version of the public health application used in the military might be like the suggestion used for the HICB treatment. It would not be unusual for noncriminal directorates to oversee gang and extremist related activities. Medical specialists could categorize and track the progress of enlisted gang members, in coordination with many other administrative and investigative agencies, and report, as needed, to military leadership.
Pioneered in Boston, Massachusetts, the approach known as pulling levers was designed to influence the behavior and environment of chronic offenders. The strategy attempted to prevent gang violence by making would-be offenders believe that severe consequences would follow. It was originally named the Boston Gun Project, noting that while gang members made up less than one percent of the overall youth population, they accounted for more than 60 percent of youth homicides—often with a handgun.
This strategy was used in programs like Operation Ceasefire, a problem-oriented deterrence program that used a zero-tolerance approach. It involved rounding up offenders and holding a community meeting to explain the consequences of their continued criminal actions (i.e., long and arduous prison sentences). Much success has been realized by this approach. A key element is the delivery of a direct and explicit “deterrence” message regarding what behavior provoked a special response, and what that response was. A version of the pulling levers approach in the military might also be used with potential gang-affiliated recruits. Instead of trusting the system to “fix” the offender, the approach would entail a similar treatment plan and follow-up to the HICB program. The threat of “brainwashing” posed by drill sergeants of old is not what is being suggested. Instead, a contract with an individual sincerely seeking a way to exit the endless cycle of violence that plagued the gang life is recommended. There should be a long-term commitment on both sides, with checks and balances (perhaps annual psychological evaluations and polygraph examinations) to ensure against a reversion.
These suggestions and observations have not been previously applied to MTGMs in the military, nor has any other possible solution. As advanced gangs, like those identified by Sullivan and Bunker as Third Generation (3GEN) Gangs, continue to evolve and influence governance and state interaction, it is time for the U.S. to respond to this threat to national security. The NGIC has repeatedly reported business interactions between street gangs and Drug Trafficking Organizations (DTOs). Those same connections exist with OMGs. Such corporate-like criminal partnerships should be counteracted with a plan that is based on more than just an annual report without analysis.
Although the increasing number of MTGMs is troubling news to both criminal justice practitioners and the community, the majority of the population does not realize that this trend is occurring, nor are they aware of the seriousness of the threat to the safety of their communities. Survey results regarding the perception of MTGM presence in the Western United States are included, as are the results of the most recent Gang and Domestic Extremist Activity Threat Assessment (GDEATA) by the U.S. Army and the Federal Bureau of Investigation’s (FBI) National Gang Intelligence Center (NGIC). The connection of street gangs, OMGs, and DTEs to the military was examined, as were possible remedies for limiting the dangerousness of those criminals in the community. The note is intended to promote the awareness of the MTGM situation and encourage scholars and practitioners to conduct research concerning this issue in other locations in the United States and foreign nations towards identifying strategies to control the problem or mitigate the effects. The confluence of gangs and the military presents significant social and security challenges with significant national and global security potentials.
National Gang Intelligence Center [NGIC]. (2005-2017). National Gang Reports 2005-2017. Washington, DC: National Gang Intelligence Center.
Carter F. Smith (2017). Gangs and the Military: Gangsters, Bikers, and Terrorists with Military Training. Lanham, MD: Rowman & Littlefield.
N.B. Excerpts from the author’s book Gangs and the Military: Gangsters, Bikers, and Terrorists with Military Training are included in this note.
 National Gang Intelligence Center [NGIC]. (2013). National Gang Report - 2013. Washington, DC: National Gang Intelligence Center, https://www.fbi.gov/file-repository/stats-services-publications-national-gang-report-2013/view .
 Carter F. Smith (2017). Gangs and the Military: Gangsters, Bikers, and Terrorists with Military Training. Lanham, MD: Rowman & Littlefield.
 Carter F. Smith (2018). “Gangs and the Military Note 1: The Increased Threat of Third Generation Gangs with Military Trained Gang Members.” Small Wars Journal, 18 April, https://smallwarsjournal.com/jrnl/art/gangs-and-military-note-1-increased-threat-third-generation-gangs-military-trained-gang.
 Smith, Gangs and the Military.
 George W. Knox, (2006). An introduction to gangs (6th ed.). Peotone, IL: New Chicago School Press.
 Karen J. McMaster (1994). An analysis of the "our gang" syndrome on a military base community and implications for educational leaders. Unpublished doctoral dissertation, The University of Arizona.
 Secretary of the Army. (1996). The Secretary of the Army’s Task Force on Extremist Activities: Defending American Values, Washington, DC: U.S. Department of Defense, 21 March p. 34, para. 16, https://www.hsdl.org/?view&did=28893.
 U.S. Army Criminal Investigations Command. (2013). Gang and Domestic Extremist Activity Threat Assessment (GDEATA), Fiscal Year 2012 (FY12).
 U.S. Army Criminal Investigations Command (2018). Gang and domestic extremist activity threat assessment (GDEATA), Fiscal Year 2017 (FY 17).
 Carter F. Smith and Joshua Harms (2018). The Threat of Street Gangs, Outlaw Motorcycle Gangs, and Domestic Terrorist/Extremist Groups with Military-Trained Members. Small Wars Journal, 23 March, https://smallwarsjournal.com/jrnl/art/threat-street-gangs-outlaw-motorcycle-gangs-and-domestic-terroristextremist-groups.
 National Gang Intelligence Center [NGIC]. (2015). National Gang Report - 2015. Washington, DC: National Gang Intelligence Center, https://www.fbi.gov/file-repository/stats-services-publications-national-gang-report-2015.pdf/view.
 G. David Curry, Scott. H. Decker, S, and David C. Pyrooz (2014). Confronting gangs: Crime and community (3d ed.). New York, NY: Oxford University Press.
 Chantal Di Placido, Terri L. Simon, Treena D. Witte, Degiang Gu, and Stephen C.P. Wong, (2006). “Treatment of Gang Members Can Reduce Recidivism and Institutional Misconduct.” Law and Human Behavior, 30(1), 93–114. DOI: 10.1007/s10979-006-9003-6.
 Bill Sanders (2017). Gangs: An introduction. New York, NY: Oxford University Press.
 Anthony A. Braga. (2008). Pulling levers: Focused deterrence strategies and the prevention of gun homicide. Journal of Criminal Justice, 36, 332–343. doi:10.1016/j.jcrimjus.2008.06.009, https://www.uc.edu/ics/crimereduction/jcr%3Acontent/MainContent/download/file.res/Braga%20Pulling%20Levers.pdf
 John P. Sullivan and Robert J. Bunker (2007). “Third generation gang studies: An introduction.” Journal of Gang Research, 14(4), pp. 1-10. Retrieved from https://scholarship.claremont.edu/cgu_fac_pub/136/.
 National Gang Intelligence Center [NGIC] (2017). National Gang Report - 2017. Washington, DC: National Gang Intelligence Center.