1

No. 1 February 2007

INTRODUCTION

This report presents new information on the long-term 

trend in street gang activity and violent crime in the 

United States. The major focus of the trend analyses 

reported here is on the ebb and flow of gang activity 

in U.S. cities and counties of varying sizes. For the 

first time, trajectory analysis,i which can group cities 

according to common patterns, is used to examine cities’ 

and other localities’ histories of gang problems as a way 

of gaining insights into gang activity across multiple 

years. In the second section of this report, attention is 

turned to large cities’ violent gang histories.

A BRIEF HISTORY OF GANG 

ACTIVITY IN THE UNITED 

STATES

Street gangs did not develop uniformly across the United 

States. Serious gangs first emerged on the East Coast 

in the 1820s, led by New York City (Howell and Moore, 

2010). A half-century would pass before gangs emerged 

in the Midwestern (Chicago) area and Western (Los 

Angeles) regions, which would see significant gang 

development a full century later than New York City. The 

South would not experience significant gang problems 

for almost another half-century, starting in the 1960s. 

Brief summaries of gang emergence in each of the major 

geographic regions follow. 

Eastern Region. The first gang-like groups began to 

emerge in New York City immediately after the American 

Revolution ended in 1783, but they were not seasoned 

criminals; only youngsters fighting over local turf 

(Adamson, 1998; Sante, 1991). The beginning of serious 

ganging in New York City would commence a few 

years later, around 1820, following far more large-scale 

immigration. The early white European ethnic gangs of 

New York City inevitably emerged from wave after wave 

of immigrants (Sante, 1991) and extreme economic and 

social conditions characterized as “hypoghettoization” 

(Adamson, 2000). Street gangs dominated by adult 

barroom brawlers were entwined with organized crime 

and political corruption in a symbiotic relationship 

(Sante, 1991). “Immigrant children, who found 

themselves caught between the old-world communal 

practices of their parents and the norms of an often 

hostile host society, frequently got together in corner 

groups and gangs” (Adamson, 2000, p. 276). Nearly 

50 Philadelphia gangs were identified between 1840 

and 1870 by Philadelphia’s Public Ledger (Adamson, 

1998, p. 62). Boston also saw gangs form in the North 

End and Fort Hill areas before the Civil War (Adamson, 

2000). Another wave of gang activity developed in the 

Eastern region during the 1950s and 1960s after Latino 

and black populations arrived en masse. For a time, 

broadcast media dubbed Philadelphia the “youth gang 

capital” of the nation (Ness, 2010, p. 32). During the 

1980s, many of the new immigrants into New York City 

were Asian and non-Puerto Rican Latinos—especially 

Dominicans followed by Central and South Americans 

(Sullivan, 1993, pp. 8–9). Gang culture travelled outward 

from New York City in the Eastern corridor, engulfing 

major cities from Pennsylvania to Connecticut. 

Midwest Region. Gangs that flourished in Chicago in 

the early part of the 1900s grew mainly from the same 

immigrant groups that populated the early serious street 

gangs of New York City (Thrasher, 1927). Polish and 

Italian gangs were most numerous among Chicago’s 

first gangs. Street gangs were said to “prosper in 

the very shadow of organized crime mobs” (McKay, 

1949, p. 36). Perkins (1987) found evidence of White 

gangs “roving the streets” of Chicago as far back as 

the 1860s, but violent black street gangs did not have 

a notable presence until the 1960s. The second period 

of gang growth in Chicago commenced in the 1930s 

after a steady migration of Mexicans and blacks to 

northern cities. The post-World War II period also saw 

another surge of Mexican and Latino workers move into 

Midwest cities, including Chicago and Detroit (Pachon 

and Moore, 1981). Mexican immigrants spread into 

Chicago communities that had long been settled by 

the Irish, Germans, Czechs, and Poles, wherein Latino 

gangs grew to join the ranks of the most violent gangs 

in the city (Spergel, 2007). Soon, “the Chicago style 

of gangsterism” would stretch “to Gary, Indiana, and 

Milwaukee, Wisconsin, where alliances are fragile 

enough to promote inter-racial mistrust and solid 

enough to fuel feuds lasting for decades” (Cureton, 

2009, p. 354).

No. 6 May 2011

Bureau of Justice Assistance

U.S. Department of Justice

National Gang Center Bulletin

U.S. Gang Problem Trends and Seriousness,

1996–2009

By: James C. Howell, Arlen Egley, Jr., George E. Tita, and Elizabeth Griffiths
2

Western Region. Gang-like groups are said to have first 

appeared in the Western region as early as the 1890s 

(Redfield, 1941; Rubel, 1965). These nascent gangs 

appear to have migrated along the trail that originated 

in Mexico and continued along a route through El Paso 

and Albuquerque, and onward to Los Angeles. This 

trail would later come to resemble a well-traveled road, 

carrying gang culture back and forth between Mexico, 

Central America, and Los Angeles. The MexicanAmerican gangs in the barrios (neighborhoods) of East 

Los Angeles typically formed in adolescent friendship 

groups in the 1930s and 1940s (Moore, 1993). These “boy 

gangs” were transformed into street gangs (Vigil, 1988, 

1990, 2002), which drew most of their strength from 

their own ethnic history. A second period of massive 

immigration of Mexicans into Los Angeles from 1940 to 

the 1970s gave rise to more Mexican-American gangs. 

In a third stage, the development of black gangs in Los 

Angeles was fueled by the “great migration” of black 

people out of the Southern states, spawning the Crip 

and Blood gangs in Los Angeles. The Los Angeles gang 

culture soon began to draw the attention of youth in 

nearby cities. By the 1970s, street gangs had emerged 

in most populated areas across California (Miller, 

1982/1992, pp. 35–36), and two of the city’s largest 

gangs, MS-13 (originally Salvadoran) and 18th Street 

(Mexican-American), would be dubbed “transnational 

gangs” as a result of the movement of some of their 

members to and from Mexico, Central America, and the 

West and Southwest (Howell and Moore, 2010). 

Southern Region. The Southern region emerged much 

later as an important gang territory. First, it lacked a 

central large city that could have provided a springboard 

for gang growth. For many years, San Antonio was 

the only large city, but it was too isolated to extend 

its gang influence (Telles and Ortiz, 2008). Second, 

the early immigrant groups were dispersed across 

the area. Hence, significant gang activity likely did 

not emerge in the Southern states prior to the 1970s 

(Miller, 1982/1992). Toward the end of that decade, 

only five Southern cities reported gang activity (Dallas, 

Fort Worth, New Orleans, Miami, and San Antonio) (pp. 

42, 110). However, before the end of the 20th century, 

the Southern region matched the other major regions 

in the prevalence of gang activity, but gang problems 

remained dispersed across the region (Miller, 1982/1992, 

Miller, 2001). From the 1970s through 1995, this region 

led the nation in the number of new gang cities (a 32 

percent increase), versus increases of 26 percent in the 

Midwest, 6 percent in the Northeast, and 3 percent in 

the West (Miller, 2001, p. 32).

Recent regional trends in gang activity are shown in the 

sidebar on page 13.

Early Multicity Gang Surveys

Miller’s study (1982/1992) provides the national baseline 

of early multicity gang survey research. His studies 

were conducted against a backdrop of very limited 

knowledge of gangs in the United States. Only two 

previous efforts had been made to assess the gang 

problem in multiple cities. Bernstein (1964) examined 

gang problems in nine major cities in 1962, although not 

for the purpose of assessing gang characteristics; only 

to explore solutions. Simultaneous with Miller’s 1982 

survey, Needle and Stapleton (1983) surveyed 60 police 

departments in 1980, although the central purpose was 

to evaluate methods they were using to suppress and 

control gangs. Subsequent single-year gang surveys 

encompassed major cities (see Curry and Decker, 2003, 

pp. 17–30; Howell, 1994; Miller, 2001). 

At the time of Miller’s research, gang knowledge was 

based largely on a New York-centered picture of gang 

evolution: growth in the 1950s, demise in the 1960s, 

revival in the early 1970s, and dormancy in the later 

1970s (Miller, 1982/1992, 2001). The popular perception 

was that the New York sequence of events applied 

to other cities. Miller’s pilot study (1975) found this 

assumption to be seriously flawed. He found high levels 

of gang violence in 6 of the 12 largest cities in the United 

States. Hence, Miller’s gang survey was expanded to 

encompass 26 cities (1982/1992). Based on this study, 

Miller (1990) recommended the creation of a federal 

center for statistically tracking and monitoring gang 

activity. The National Youth Gang Center (NYGS) was 

established in 1995 along with other federal anti-gang 

programming, following comprehensive reviews of gang 

research, programs, and policies (Howell, 1994; Kelley, 

1994; Miller, 1990).

GANG PROBLEM PREVALENCE 

TRENDS, 1996–2009

The National Gang Center (NGC)ii has tracked the 

distribution and level of the gang problem in the United 

States since its first nationally representative National 

Youth Gang Survey (NYGS), in 1996. The NYGS is the 

first gang survey in any country that annually contacts 

a nationally representative sample of authoritative 

respondents in their respective jurisdictions regarding 

the prevalence and characteristics of gang activity 

using the same methodology each year. With the 

accumulation of 14 years of data, this report provides a 

long-term view of data generated in the NYGS, covering 

the time period from 1996 to 2009. iii 

The 14-year gang prevalence trend shown in Figure 1 

demonstrates that gang activity remains a widespread 

problem across the United States. By 2009, prevalence 

rates were significantly elevated compared with 

recorded lows in 2000 and 2001. Approximately onethird of the jurisdictions in the NYGS study population 

experienced gang problems in 2009, compared with 

under one-quarter in 2002, an increase of more than 

20 percent in the estimated number of gang-problem 

jurisdictions between 2002 and 2009.
3

Figure 2 shows the prevalence of gang activity within 

each of the four NYGS subsamples (see Appendix A 

for sample details). Each subsample follows a similar 

trend over time, albeit at noticeably different levels. 

Larger cities consistently exhibit the highest prevalence 

rates of gang activity among the four groups, followed 

by, in order, suburban counties, smaller cities, and 

rural counties. iv The rates of reported gang activity in 

suburban counties are closest to the rates for larger 

cities because of the relatively large populations in 

Figure 1. Prevalence of Gang Problems in Study Population, 1996–2009

Note: Gang problems are measured by respondents’ affirmative response that youth gangs 

were active in their jurisdictions during the past year.

suburban counties (i.e., a high capacity to sustain gang 

activity, Egley et al., 2006), the shifting of previous 

inner-city slums and ghettos to ring-city or suburban 

areas (Miller, 1982/1992, pp. 75–76), and the growing 

popularity of gang culture in these areas (Miller, 2001). 

Mirroring the overall trend displayed in Figure 1, each 

of the subsamples shows uniform declines in the late 

1990s, reaching a low point in 2001 and then steadily 

increasing before leveling off in recent years. 
4

Grouping Jurisdictions by Gang-Problem 

Patterns 

Gang-problem patterns within jurisdictions are further 

examined here through trajectory modeling, which 

groups jurisdictions that share similar trends in the 

outcome of interest (specifically, gang activity and gangrelated homicides) and graphically illustrates those 

patterns over the 14-year survey period. For example, 

some jurisdictions may report a consistent presence of 

gangs, while others could experience no gang activity 

over time, rapid increases over time, rapid decreases, 

fluctuating presence of gang activity, or other more 

complex trends between 1996 and 2009.

Figure 2. Law Enforcement Agency Reports of Gang Problems by Area Type, 

1996–2009

The first trajectory model (Figure 3) displays trends 

in the presence of gang activity across the 1,517 

jurisdictions included in both the first and current 

NYGS samples.v Of the total, 664 (43.8 percent) of the 

jurisdictions fall into the first trajectory (T1). This group 

exhibited a relatively lower prevalence of gang activity 

in 1996, which declined precipitously until 2001 before 

experiencing some growth that continued through 2009. 

By contrast, more than half (N=853; 56.2 percent) of the 

jurisdictions reported a near-chronic presence of gang 

activity across the time period (T2). Thus, this trajectory 

model reveals that a small majority of all respondents 

reporting gang activity have a persistent gang problem 

which, apart from the minor deviation in 2001, has 

remained virtually constant over time. 
5

Previous NYGS analysis has firmly demonstrated that 

gang activity—in terms of size of gang membership 

and the occurrence of gang violence—remains largely 

concentrated in the most populated areas in the United 

States (Egley, Howell, and Major, 2004, 2006; Howell and 

Egley, 2005; Howell, 2006). Therefore, the next analysis 

focuses only on jurisdictions with populations greater 

than 50,000. This permits an examination of areas with 

more persistent gang activity for distinctive trends—

where gang activity is not only more prevalent, but also 

more serious, and thus more revealing with respect to 

common patterns. 

Figure 4 displays the six identifiable groups uncovered 

in the analysis of this smaller sample of 598 localities 

(versus 1,517 in the previous analysis). The most 

predominant group is T5 (69.9 percent), which reported 

a persistent and chronic gang problem over the 14-year 

period. The remaining five groups showed widely 

varied trends in gang activity. Three of these groups 

(T3, T4, and T6) all showed substantial declines in gang 

activity from 1996 to 2000. However, each experienced 

a very different trend after year 2000. Among these 

three groups, one group (T4; 6.5 percent) continued to 

experience steady declines in gang prevalence which 

leveled off somewhat in recent years. Declines for the 

one group (T6; 5.4 percent) continued for two more years, 

to the point that by 2002, virtually no presence of gang 

activity remained.

In stark contrast, the reductions in the presence of gang 

activity evidenced between 1996 and 2000 for the last 

of these three unique trajectory groups (T3; 9.2 percent) 

were short-lived, since the presence of gang activity 

rose sharply thereafter to near saturation in recent years.

The remaining two groups of jurisdictions (T1 and T2) 

exhibit an opposite pattern, beginning with virtually 

no gang activity at the start of the 14-year period, 

and experiencing increases (at different rates) over 

time. More specifically, the first group (T1; 4.2 percent) 

exhibited small yet steady increases in gang activity. 

The second trajectory group (T2; 4.8 percent), however, 

started the period with virtually no reported gang 

activity but experienced a steep rise after onset in 1998 

(similar to that of T3) that continued upward to complete 

persistence toward the end of the period. 

Several conclusions can be drawn from this trajectory 

analysis. First, for most (over two-thirds) of the cities 

with populations of 50,000 or more, prevalence rates 

of gang activity have remained unchanged for the 

past decade and a half. By comparison, this observed 

consistency is rare in smaller localities (Howell and 

Egley, 2005), where gang activity is more transitory and 

less serious over time. Second, the remaining one-third 

of the large cities examined here exhibit widely varying 

trends. Some agencies have experienced substantial 

declines or the complete desistence of gang activity, 

while others have exhibited rather extraordinary 

increases since the turn of the century. 

Notes: Data from the NYGS 1996 through 2009; best-fitting model includes two 

groups with quadratic polynomial functions (BIC = -7416.92). Jurisdictions 

reporting the presence of gang activity were coded as 1, and those reporting no 

gang activity were coded as 0 at each year. 

Figure 3. Trajectory Model

Presence of Gang Activity

Jurisdictions included in the NYGS between 1996 and 2009 (N=1517)
6

Figure 4. Trajectory Model

Presence of Gang Activity

Jurisdictions with 50,000+ in 2002 and 1996–2009 Data (N=598)

Note: Data from the NYGS 1996 through 2009; best-fitting model includes six groups with 

quadratic polynomial functions (BIC = -1892.99).

Unfortunately, at this point, explanations are not 

available for the trends observed above because of 

the novelty of this research. Our purpose in this initial 

application of trajectory analysis is to develop an 

understanding of the varied trends in persistent gang 

activity across cities. Next, we turn to apply trajectory 

analysis to analysis of serious gang problem cities.

SERIOUS GANG PROBLEM 

TRENDS

The above analyses demonstrate that cities can be 

grouped in terms of their distinctively patterned gang 

problem histories. With this in mind, the next step is to 

assess the relative seriousness of gang activity among 

cities. For the purposes of this analysis, homicide is 

considered to be a primary indicator of serious gang 

activity.

Gang-Related Homicides and Serious Gang 

Activity

While homicides notably characterize serious gang 

problem cities more than any other factor, it is important 

to note that gang homicides are heavily concentrated 

geographically in the United States. Most cities have 

no gang homicides, and those that do usually report 

very few of them from year to year (Egley et al., 2006). 

Rather, it is in a subset of very large cities where the 

overwhelming majority of them occur, as this report 

shows. Previous research has shown that these gang 

homicides tend to occur in spurts, governed by episodic 

gang conflicts that wax and wane and sometimes extend 

over a number of years (Block and Block, 1993; Decker, 

1996, 2007; Howell and Moore, 2010; Miller, 1982/1992; 

Papachristos, 2009). The use of firearms in assaults, 

of course, increases the likelihood of these events 

resulting in lethal violence in contrast to nonlethal injury. 

Beginning in the 1980s, youth gangs were reported to 

have more weapons of greater lethality (Block and Block, 

1993; Block, Christakos, Jacob et al., 1996; Decker, 2007; 

Howell, 1999; Hutson, Anglin, Kyriacou, et al., 1995; Tita 

and Abrahamse, 2004, 2010). In an earlier analysis of 

NYGS data, jurisdictions experiencing higher levels of 

gang violence—evidenced by reports of multiple gangrelated homicides over survey years—were significantly 

more likely than those experiencing no gang homicides 

to report more pervasive and frequent firearm use by 

gang members in assault crimes (47 percent versus 4 

percent of the jurisdictions, respectively) (Egley et al., 

2006).

The trajectory analysis presented in Figure 5 examines 

trends in the proportion of all homicides that are gangrelated and, in contrast to the previous section of 

this report, offers a more pointed investigation of the 

seriousness of gang problems nationwide. Further, the 

analysis that follows is limited to cities with populations 

in excess of 100,000 persons and incorporates total 

annual homicide counts from the Uniform Crime Report 

(UCR) data for all very large cities participating in the 
7

NYGS between 1996 and 2009. Overall, 247 cities 

met the criteria for inclusion.vi Proportional homicide 

rates—along which cities’ patterns are aligned here—

were determined by dividing the total number of gang 

homicides reported in the NYGS annually by the total 

number of homicides reported for the city in the UCR, 

multiplied by 100. 

Figure 5 shows the results from the trajectory analysis 

of these cities, where five groups of distinctive trends 

were found in the percentage of homicides that were 

gang-related between 1996 and 2009. Two of these 

groups (T3 and T5) show sharp increases, while the 

remaining three groups (T1, T2, and T4) show relatively 

stable trends, albeit at significantly different levels. For 

the group of cities with the largest frequency (T2; 42.5 

Figure 5. Trajectory Model 

Percent of Homicides That Are Gang-Related

Cities with 100,000+ Population (N=247)

Note: Data from the NYGS 1996 through 2009 and UCR 1996 through 2009. The bestfitting model includes five groups with linear polynomial functions (BIC = -7348.85).

percent), nearly one in five homicides were gang-related 

annually over the 14-year period. For the second largest 

group (T4; 28.7 percent), approximately 40 percent of 

the homicides (or twice the rate of T2 cities) were gangrelated. An additional 6.5 percent of the agencies (T3 

and T5) showed increases over time, while only one 

group (T1; 22.3 percent) exhibited little to no lethal 

gang violence.

The total set of 247 cities represented in this analysis is 

shown in Appendix C. Note that these cities are listed in 

the trajectory group in which the analysis places them. 

This listing is provided for the benefit of stakeholders 

in the respective cities who wish to consider this 

information further in local strategic planning activities.

Three noteworthy observations can be made by 

analyzing gang-related homicides as a proportion of the 

total number of homicides reported in the UCR for very 

large cities. First, almost eight out of ten cities with 

populations greater than 100,000 regularly report gang 

homicides. Second, a remarkable degree of consistency 

in the rate of gang-related homicides across trajectory 

groups is observed. None of the groups found in these 

cities displayed a pattern consistent with a decline 

in the prevalence of gang homicide. Third, in the two 

largest groups (T2 and T4), comprising 70 percent of 

all the cities, between 20 percent and 40 percent of all 

homicides annually were found to be gang-related. 

These findings beg an important question: Are many 

gang homicides concentrated in one or more regions 

of the United States? Map 1 takes the five trajectories 

and maps their locations. While Trajectory 5 is limited 

to two California cities (the less-urban Salinas and the 

densely populated, urban Inglewood), the remaining 

cities exhibiting varied gang seriousness trajectories 

appear to be randomly distributed across geographic 

regions of the United States. Most clusters of reporting 

cities (e.g., the Bay Area of California, Los Angeles Basin, 

Great Lakes Region, Northeast, and Florida’s Atlantic 

Coast) contain jurisdictions following at least three of 

the different trajectories. Therefore, with the exception of 

these five clusters (and Chicago and Los Angeles, which 

are examined below), one can conclude that very large 

cities with consistently high levels of gang homicides are 

widely dispersed across the United States. 
8

Map 1. Spatial Distribution of Trajectory Analysis for Gang-Related Homicide 

in Large Cities, 1996–2009

In the next section, we provide a case study of one very 

large city, Pittsburgh, to gain some insights regarding 

the histories of cities with chronic, violent gang histories.

PITTSBURGH ILLUSTRATION

Pittsburgh appears to be somewhat typical among 

very large cities (populations greater than 100,000) 

with respect to the long-standing seriousness of its 

gang problem. Before examining its history, we pause 

to reveal Pittsburgh’s location in the above trajectory 

sets. Pittsburgh is among the cities in Trajectory Group 

2 (Figure 3) that consistently experienced gang activity 

throughout the 14-year survey period 1996–2009. As 

expected, because of its size, Pittsburgh is among 

the cities with populations above 50,000 shown in 

Figure 4, and it is located in Trajectory Group 5, again 

consistently reporting gang activity. Finally, Pittsburgh 

is representative of the very large cities in the Trajectory 

4 group (Figure 5 and Map 1) that reported a high level 

of gang homicides (approximately 40 percent of total 

annual homicides, on average) during 1996–2009.

From other NYGS analyses, we know that Pittsburgh is 

one of 28 cities with populations greater than 100,000 

that reported onset of gang activity in the period 

1991–1992; it is generally considered a “late onset” city 

(Howell, Egley, and Gleason, 2002). However, unlike 

other cities in the late onset group, Pittsburgh quickly 

developed a serious gang problem. Its gang activity 

developed in two stages, which are characterized here 

as early emergence and recent gang activity.

Emergence of Gang Activity in Pittsburgh

A surge in drug-related arrests (apparently driven by 

crack cocaine offenses) preceded the emergence of 

gang activity in Pittsburgh (Tita, 1999; Cohen and Tita, 

1999).vii Almost immediately following the emergence 

of gang activity, homicides began growing “across 

spatially independent but socially similar Pittsburgh 

areas (specifically, fractured, high poverty, African 

American communities)” (Tita and Cohen, 2004, p. 

200). Interestingly, “shots-fired” calls viii spontaneously 

increased in “a classic epidemic” during a pregang 

period (1990–1991) in census tracts ix distributed widely 

throughout the city (p. 195). Tita and Cohen observed 

that it was precisely in the high-violence communities 

where gangs emerged. 

Violent urban street gangs, including sets (subgroups) of 

Crip and Blood gangs, began to take hold in Pittsburgh 

during the latter half of 1991 (Tita and Cohen, 2004). 

All of the hard-core sets had black gang members 

(Tita, Cohen, and Engberg, 2005). Gang emergence 

continued through 1993 and stabilized in 1994–1995 

with no new gangs forming and no gangs desisting. 

The emergence of youth gangs “was followed by a 

contagious spread of shots fired activity in gang tracts 
9

or tracts adjoining them,” fueling an epidemic of gun 

violence or “contagious diffusion” to other areas (Tita 

and Cohen, 2004, p. 195). In addition to spawning a 

number of gang homicides, these murders seemingly 

precipitated a more general class of nongang youth 

homicides. 

Perhaps largely attributable to the violent community 

context within which they formed, “all of the gangs 

included in this [Pittsburgh] study share one thing 

in common: They are known to be violent” (Tita and 

Ridgeway, 2007, p. 217), and they have earned “respect” 

and fear from the community (Tita, 1999). Given the 

territorial and retaliatory natures of urban youth gang 

violence (Block and Block, 1993; Decker, 2007; Rosenfeld, 

Bray, and Egley, 1999; Hughes and Short, 2005), it is 

reasonable to expect that gang-related violence would 

follow predictable spatial and temporal patterns. In 

short, “one might expect set space to serve as a sort 

of lightning rod for intergang violence” (Tita and 

Ridgeway, 2007, p. 217). From the onset of gang activity 

in Pittsburgh, about two-thirds of all gang homicides 

were gang-motivated. x

Recent Gang Activity in Pittsburgh

Tita and colleagues’ on-site study of Pittsburgh ended 

in 1995. This section summarizes the Pittsburgh 

Bureau of Police’s responses to the National Youth Gang 

Survey from 1996 onward. Beginning in 1996, a wellpublicized Federal Racketeer Influenced and Corrupt 

Organization Act indictment of a local street gang “had 

an enormous impact on all Pittsburgh gangs. Gangs 

and gang violence virtually disappeared from the streets 

of Pittsburgh” (Tita et al., 2005, p. 281). From 1996 to 

1999, the number of gangs reported by the Pittsburgh 

Bureau of Police dropped 77 percent, from 86 to just 20. 

For several years thereafter, the Pittsburgh Bureau 

of Police’s responses to the NYGS characterized the 

city’s gang problem as somewhat stabilized and at a 

serious level, particularly in drug trafficking, aggravated 

assault, and firearm use. Law enforcement considered 

a majority of the gangs to be “drug gangs.” The 

proportion of gang members that is black has remained 

virtually unchanged over the 14-year period, averaging 

almost 86 percent. Gangs still were well-established 

in certain areas of the city as at the beginning of the 

new millennium, with subgroups based on age, gender, 

and geographical area. Then the gang problem became 

noticeably larger and turned more serious. In six out of 

nine years (from 2001 to 2009), the Pittsburgh Bureau 

of Police reported that the city’s gang problem was 

“getting worse” in three main respects. 

First, law enforcement reported more gangs from the 

middle of this decade onward, which likely contributed 

to increased intergang conflicts and gang violence. 

While only 20 gangs were counted in 1999, an average 

of 36 was reported each year during 2001–2009. This 

is a conservative estimate because Pittsburgh police 

count multiple sets as one gang. Although police had 

more difficulty estimating the number of gang members 

during the early part of this decade, during 2005–2008 

an average of 869 gang members were reported each 

year. The few very large gangs were estimated to have 

between 95 and 200 members. 

Second, gang members apparently remained in the 

gangs for multiple years. In the 1990s, police had 

estimated that seven out of ten gang members were 

juveniles. By 2008, this proportion had dropped to 

one-half. 

Third, inmates returning from prison may have 

reconnected with some of the gangs or joined outright 

as a result of relationships they formed in prison. Survey 

respondents said the returning inmates influenced local 

gang activity in important ways in the new decade, 

including drug trafficking, access to weapons, and 

violence itself. Three-fourths of these former inmates 

were estimated to be adults. From 2003 to 2006, the 

Pittsburgh Bureau of Police reported more than 20 gang 

homicides each year along with increases in gangaggravated assaults. 

In sum, Pittsburgh’s gang problem developed quickly 

and worsened measurably over time. Early gang 

emergence was preceded by widespread drug dealing 

and gunplay. Gangs emerged in the high-violence 

communities, followed by a contagious spread of shotsfired activity in gang tracts or tracts adjoining them. 

Once the gangs developed a reputation for violence and 

earned respect for this, gang violence stabilized, but at 

a high level. Now, inmates returning from prison appear 

to be refueling existing gangs. 
10

AN ANNUAL SNAPSHOT OF GANG 

HOMICIDE IN THE LARGEST 

CITIES

In this final section, we explore some dimensions of 

the current concentration of high homicide levels in 

very large U.S. cities. Chart 1 shows the total percent 

of homicides that were gang-related among cities 

with populations of 100,000 or more in 2009 (for which 

homicide data were reported). Separate figures are 

Chart 1. Gang Homicide Prevalence, Cities With 

Populations of 100,000 or More, 2009

presented for Chicago and Los Angeles because of their 

historically high numbers of gang homicides. Overall, 

approximately one-quarter of all homicides in these 

cities were gang-related. By comparison, one-half of the 

homicides in Los Angeles and one-third of the homicides 

in Chicago were gang-related in 2009.
11

group excludes Chicago and Los Angeles). In other 

words, the serious gang homicide problem in the 

United States extends far beyond these so-called “gang 

capitals,” and is disproportionately found in cities with 

higher murder rates throughout the nation.

Cumulative Gang-Related Homicides 

Map 2 shows the locations of cumulative gang-related 

homicides, shaded according to rate (per 1,000 gang 

members) that all NYGS respondents reported across 

the 2002–2009 surveys. Given the large number of 

reported gang members in such “chronic gang cities” 

as Los Angeles and Chicago, it is not surprising that 

Chart 2. Gang Homicide Rates, Cities With 

Populations of 100,000 or More, 2009

Chart 2 displays findings on homicide concentration 

from another viewpoint. First, the overall homicide 

rate for each of the 282 very large cities was calculated 

from the UCR and then placed into quartiles. Next, total 

gang homicide counts for cities within each quartile 

were calculated. This analysis finds that for cities with 

the lowest homicide rate (i.e., 1st quartile), a total of 

23 gang homicides were reported. In cities with the 

highest homicide rate (4th quartile), nearly 400 gang 

homicides were reported (note that this highest-rate 

the rate is comparably low in these areas.xi While 

counties with high rates of gang homicide per 1,000 

gang members are generally spread throughout the 

United States, there does appear to be a “high rate belt” 

in the Midwest-Great Lakes corridor and the Northeast 

Atlantic region. 

Readers should be mindful, however, that counties with 

very few reported gang members will exhibit extremely 

high rates of violence with only very few homicides 

(which analysts call the “tyranny of small numbers” 

principle). The ten counties displayed in Table 1 have 

the highest gang homicide rates in the United States 

during 2002–2009, as determined by data provided to 

the National Youth Gang Survey. The highest rate of 

all, in Nash County, North Carolina, is attributable to 

a small number of gang homicides and relatively few 

gang members. Two other counties in this listing stand 

out for having a high gang homicide rate for this same 

reason, even when the actual number of homicides is 

very small (13 in Richland County, South Carolina, and 

just three in Cumberland County, Maine). Each of these 

ten counties is shaded darkest in Map 2.
12

Map 2. Rate of Gang-Related Homicides 

(Per 1,000 Gang Members), 2002–2009

Table 1. Ten Counties with the Highest Gang Homicide Rates, 

2002–2009

County Rate Number of Homicides

Nash, North Carolina 111.8 19

San Francisco, California 97.5 195

Baltimore, Maryland 88.3 53

Richland, South Carolina 76.5 13

Montgomery, Ohio 70.0 28

Saginaw, Michigan 63.3 57

Oakland, Michigan 60.1 16

Cumberland, Maine 42.8 3

Bibb, Georgia 42.5 17

Allen, Indiana 40.9 19
13

Regional Trends in GangXii Activity as Viewed 

by the FBI and Police Agencies

Northeast Region.

Xiii New York City is no longer the 

epicenter of serious street gang activity in the Northeast, 

as was the case in the early 1900s (Howell and Moore, 

2010). Gradually, gang activity in this region expanded 

to include other East Region and New England states, 

particularly Pennsylvania, New Jersey, and Connecticut 

(FBI, 2009). According to the FBI’s intelligence reports, 

“the most significant gangs operating in the East Region 

are Crips, Latin Kings, MS-13, Ñeta, and United Blood 

Nation” (p. 16). “The most significant gangs operating in 

the New England Region are Hells Angels, Latin Kings, 

Outlaws, Tiny Rascal Gangster Crips, and UBN” (p. 17).

Central Region.

Xiv In the Midwest region, traditional 

Chicago gangs still have the strongest presence. In 2008, 

the largest street gangs in Chicago included the Gangster 

Disciple Nation (GDN), Black Gangsters/New Breeds 

(BG), Latin Kings (LKs), Black P. Stone Nation, Vice Lords 

(VLs), Four Corner Hustlers, and Maniac Latin Disciples 

(MLDs) (Chicago Crime Commission, 2006, p. 11). The 

most recent chapter in Chicago’s gang history is the 

proliferation of gangs outside the city. By 2006, 19 gang 

turfs were scattered around Chicago, throughout Cook 

County (Chicago Crime Commission, 2006, p. 119). Next, 

gangs began emerging in the larger region surrounding 

Chicago on the North, West, and South sides. Other cities 

in this region that have extensive gang activity include 

Cleveland, Detroit, Joliet, Kansas City, Minneapolis, 

Omaha, and St. Louis (FBI, 2009, p. 18).

Pacific Region.

Xv Street gangs in Los Angeles remain 

legendary. Los Angeles is now said to be “the gang 

capital of the world” (The Advancement Project, 2007, p. 

1). The Los Angeles Police Department (2007) recently 

designated the 11 most notorious gangs in the city: 

18th Street Westside (Southwest Area), 204th Street 

(Harbor Area), Avenues (Northeast Area), Black P-Stones 

(Southwest, Wilshire Areas), Canoga Park Alabama 

(West Valley Area), Grape Street Crips (Southeast Area), 

La Mirada Locos (Rampart, Northeast Areas), Mara 

Salvatrucha (Rampart, Hollywood, and Wilshire Areas), 

Rollin 40s (Southwest Area), Rollin 30s Harlem Crips 

(Southwest Area), and Rolling 60s (77th St. Area). 

Southern Region.

Xvi The most significant gangs operating 

in the Southeast region (Deep South states) are said to 

be the Crips, Gangster Disciples, Latin Kings, Sureños 

13, and United Blood Nation (FBI, 2009). According to 

the FBI, the increased migration of Hispanic gangs into 

the region has contributed significantly to gang growth 

(p. 20). In the Southwest region (Texas, Oklahoma, New 

Mexico, Colorado, Utah, and Arizona), the most significant 

gangs are Barrio Azteca, Latin Kings, Mexikanemi, Tango 

Blast, and Texas Syndicate (FBI, 2009). Among 25 major 

Houston gangs, the Tango Blast, Houstone Tango Blast, 

and Latin Disciples are said to be the main regional gangs 

that are Houston-based (http://www.stophoustongangs.

org).

Sources: Chicago Crime Commission (2006); FBI (2009); 

Los Angeles Police Department (2007)

CONCLUSION AND 

IMPLICATIONS

Gang activity and its associated violence remains an 

important and significant component of the U.S. crime 

problem. While it has been reasonably assumed that 

gang-related violence would follow the overall dramatic 

declines in violent crime nationally, analyses provided 

in this report find overwhelming evidence to the 

contrary—that is, gang violence rates have continued 

at exceptional levels over the past decade despite the 

remarkable overall crime drop. Gang violence that is 

rather commonplace in very large cities seems largely 

unaffected by, if not independent from, other crime 

trends—with the possible exceptions of drug trafficking 

and firearm availability (Block and Block, 1993; Block et 

al., 1996; Howell, 1999; Tita and Cohen, 2004; Tita and 

Griffiths, 2005; Tita and Ridgeway, 2007).

This study has shown that while fluctuations in the 

prevalence of gang activity are certainly evident since 

the mid-1990s to the present, much of this instability 

has occurred outside the largest U.S. cities where gang 

activity has remained concentrated and prevalence 

rates have remained nearly constant. In addition, 

and perhaps more important, the seriousness of gang 

problems in these cities has not changed appreciably 

in this period. Two distinct groups of very large cities 

(with populations greater than 100,000 persons), 

together making up 70 percent of all large cities, 

consistently reported that between 20 and 40 percent 

of their homicides were gang-related from 1996 to 2009; 

and only one group, composed of less than one-quarter 

of the cities, exhibited very few to no gang homicides 

in the study period. Moreover, reported gang-related 

homicides in these cities increased 7 percent from 2005 

to 2009 (Egley and Howell, forthcoming). 

Developing a strategic plan for intervening in gang 

homicides is complicated by gang dynamics. “Even 

labeling something as a ‘gang’ homicide masks 

important aspects that need to be understood before 

enacting policy; for example, whether the homicide 

was motivated by gang rivalry, or the protection of 

drug markets, or was merely an argument that involved 

young males who happened to be gang members” 

(Tita and Abrahamse, 2010, p. 29). These situations 

underscore the importance of making a careful 

assessment of overall youth violence and the gang 

component before developing a strategic plan (Tita, 

Riley, and Ridgeway, 2003). A user-friendly protocol 

is available that communities themselves can follow 

in conducting a communitywide assessment (Office of 

Juvenile Justice and Delinquency Prevention, 2009a). 

Analysis of the specific circumstances surrounding 

gang homicides also greatly increases the likelihood of 

successful interventions (Braga, 2004).

Several gang programs have demonstrated effectiveness 

in intervening in street-level gang violence. Only three 

of these are noted here, specifically for their capacity to 

intervene directly in violent gang incidents. The OJJDP 

Comprehensive Communitywide Approach to Gang 
14

Prevention, Intervention, and Suppression Program, 

which was later renamed the OJJDP Comprehensive 

Gang Model (Office of Juvenile Justice and Delinquency 

Prevention, 2009b), has reduced gang-related violence 

in Chicago, Los Angeles, and other sites (Hayeslip and 

Cahill, 2009; Cahill and Hayeslip, 2010; Spergel, 2007; 

Spergel, Wa, and Sosa, 2006). 

CeaseFire–Chicago is a community-level, gun-related 

violence prevention program that has demonstrated 

effectiveness in gang violence reduction, including 

homicide (Skogan, Hartnett, Bump et al., 2008). It 

specifically targets dangerous activities of carefully 

selected members of the community who have a greatly 

elevated chance of either being shot or being shooters in 

the immediate future. Program outreach workers called 

“violence interrupters” work on the streets, in hospitals, 

and other settings to mediate conflicts between gangs 

and especially individual gang members. They also 

connect would-be shooters to services and employment 

to help stem the cycle of retaliatory violence. 

In a program modeled after the Boston Operation 

Ceasefire, Los Angeles explicitly defined “triggering 

events” as any serious crimes by a gang member 

or any gang crimes in which a gun was used by the 

members of two violent gangs. The results from the 

law enforcement components were surprisingly good, 

even though the intervention did not proceed exactly 

as planned. In the area of Hollenbeck, where the 

two gangs were most active and enforcement was 

most intensive, both gang crime and violent crime fell 

(Tita et al., 2003). Despite other mixed results, the 

program “demonstrated the potential for using datadriven research to identify problems and design 

interventions, obtain the commitment of disparate 

criminal justice agencies to work together on a discrete 

problem, and secure the support of an array of partners 

in the community” (p. 2).

In most jurisdictions, improvements are needed in the 

targeting of gang violence. To aid statewide initiatives, 

Tita and Abrahamse (2010) recommended that California 

implement a gang homicide surveillance system, 

designed much like systems used by the public health 

community to monitor disease threats. The proposed 

system would provide an early warning of a rise in 

homicide victimization within particular communities, 

much like the public health model. In addition, Tita and 

Abrahamse suggest that such a homicide surveillance 

system needs to work fast enough to provide a warning 

within a few months of gang homicide onset. “It also 

needs to be fine grained with respect to geography 

and demography” (p. 29). However, reporting should 

not be delayed until a homicide is “solved,” they argue, 

because early intervention opportunities could be lost. 

In addition, such a system should capture and publish 

essential diagnostic information (including age, race, 

sex, circumstance, and census tract) about suspected 

homicide victims within a month of the event, which 

“would provide an important tool for detecting and 

reacting to upswings in violence in the state” (p. 29).” 

This is an excellent recommendation for other states 

and cities with gang-related homicides.
15

Appendix A

National Youth Gang Survey (NYGS)

Agencies included in the two nationally representative 

NYGS samples are as follows:

1996–2001 NYGS Sample

(Former Sample):

	 •	 All police departments serving cities with

 populations of 25,000 or more (n=1,216).

	 •	 All suburbancountypolice andsheriffs’departments

 (n=661).

	 •	 A randomly selected sample of police departments

 serving cities with populations between 2,500 and

 24,999 (n=398).

	 •	 A randomly selected sample of rural county police

 and sheriffs’ departments (n=743).

2002–Present NYGS Sample

(Current Sample):

	 •	 All police departments serving cities with

 populations of 50,000 or more (n=624).

	 •	 All suburbancountypolice andsheriffs’departments

 (n=739).

	 •	 A randomly selected sample of police departments

 serving cities with populations between 2,500 and

 49,999 (n=543).

	 •	 A randomly selected sample of rural county police

 and sheriffs’ departments (n=492).

Study population refers to the entire group of 

jurisdictions that the current sample represents; that 

is, all jurisdictions served by county law enforcement 

agencies and all jurisdictions with populations of 

2,500 or more served by city (e.g., municipal) police 

departments.

Sixty-three percent of the agencies in the 2002–present 

NYGS sample were also surveyed from 1996 to 2001, 

permitting an ongoing longitudinal assessment of gang 

problems in a large number of jurisdictions.

The average annual survey response rate is 

approximately 85 percent for the entire sample, as well 

as within each area type. Ninety-nine percent of the 

respondents in the current sample have provided gangrelated information in at least one survey year. Survey 

recipients were asked to report information solely for 

youth gangs, defined as “a group of youths or young 

adults in your jurisdiction that you or other responsible 

persons in your agency or community are willing to 

identify as a ‘gang.’” Motorcycle gangs, hate or ideology 

groups, prison gangs, and exclusively adult gangs were 

excluded from the survey. 
16

Appendix B

Trajectory Models

The trajectory models presented in this report are based 

on a customized SAS procedure called PROC TRAJ 

(Jones, Nagin, and Roeder, 2001; Nagin, 1999). In this 

case, we use the trajectory procedure to examine trends 

in gang presence, and gang homicide as a proportion of 

total homicide within U.S. policing jurisdictions between 

1996 and 2009. Trajectory models essentially group 

jurisdictions sharing similar trends in the outcome of 

interest and graphically illustrate those patterns over 

the period. For example, some jurisdictions may report 

a consistent presence of gangs while others could 

experience no gang activity over time, rapid increases 

over time, rapid decreases, fluctuating presence of gang 

activity, or other kinds of more complex trends between 

1996 and 2009. This methodology does not require that 

researchers specify the number of groups or the shape 

of the trajectories in advance. 
17

Appendix C

Trajectory Group 1 (N=55)

Abilene, TX 

Alexandria, VA

Amherst Town, NY

Ann Arbor, MI

Athens-Clarke County, GA

Beaumont, TX

Bellevue, WA

Billings, MT

Birmingham, AL

Cambridge, MA

Cape Coral, FL

Cary, NC

Clearwater, FL

Coral Springs, FL

Dallas, TX

Denton, TX

Erie, PA

Eugene, OR

Evansville, IN

Fort Collins, CO

Gainesville, FL

Gilbert, AZ

Hialeah, FL

Hollywood, FL

Irving, TX

Jacksonville, FL

Lexington, KY

Lincoln, NE

McAllen, TX

Mesquite, TX

Miramar, FL

Mobile, AL

Naperville, IL

Orange, CA

Overland Park, KS

Pasadena, TX

Peoria, AZ

Plano, TX

Port St. Lucie, FL

Provo, UT

Rancho Cucamonga, CA

Richardson, TX

Richmond, VA

Roseville, CA

Santa Clara, CA

Sioux Falls, SD

Springfield, MO

Stamford, CT

Tallahassee, FL

Torrance, CA

Virginia Beach, VA

Waco, TX

Warren, MI

Westminster, CO

Winston-Salem, NC

Trajectory Group 2 (N=105)

Allentown, PA

Amarillo, TX

Anchorage, AK

Arlington, TX

Arvada, CO

Atlanta, GA

Aurora, CO

Austin, TX

Baltimore, MD

Baton Rouge, LA

Berkeley, CA

Boise, ID 

Bridgeport, CT

Burbank, CA 

Carrollton, TX

Cedar Rapids, IA

Chandler, AZ

Charleston, SC

Charlotte-Mecklenburg, NC

Chattanooga, TN

Cincinnati, OH

Cleveland, OH

Colorado Springs, CO

Columbia, SC

Columbus, GA

Columbus, OH

Corpus Christi, TX

Costa Mesa, CA

Dayton, OH

Denver, CO

Des Moines, IA

Detroit, MI

El Paso, TX

Fairfield, CA

Fayetteville, NC

Flint, MI

Fort Lauderdale, FL

Fort Worth, TX

Fresno, CA

Garland, TX

Glendale, AZ

Glendale, CA

Grand Prairie, TX

Grand Rapids, MI

Green Bay, WI

Greensboro, NC

Hampton, VA 

Henderson, NV

Honolulu, HI

Houston, TX

Huntington Beach, CA

Irvine, CA

Jackson, MS

Jersey City, NJ

Kansas City, KS

Kansas City, MO

Knoxville, TN

Lafayette, LA

Lansing, MI

Laredo, TX

Las Vegas, NV

Louisville Metro, KY

Lubbock, TX

Manchester, NH

Memphis, TN

Mesa, AZ

Miami, FL

Midland, TX

Milwaukee, WI

Modesto, CA

Montgomery, AL

Nashville, TN

Newark, NJ

Norfolk, VA

Norman, OK

North Las Vegas, NV

Oakland, CA

Oceanside, CA

Olathe, KS

Omaha, NE

Orlando, FL

Palm Bay, FL

Pembroke Pines, FL

Phoenix, AZ

Portland, OR

Portsmouth, VA

Providence, RI

Pueblo, CO

Reno, NV

Rochester, NY

Rockford, IL

Sacramento, CA

San Antonio, TX

Scottsdale, AZ

Shreveport, LA

Simi Valley, CA

St. Louis, MO

St. Petersburg, FL

Sterling Heights, MI

Stockton, CA

Tampa, FL

Tempe, AZ

Vancouver, WA

Victorville, CA

Washington, DC
18

Trajectory Group 3 (N=14)

Antioch, CA

Chesapeake, VA

Concord, CA

Daly City, CA

El Monte, CA

Elgin, IL

Elizabeth, NJ

Independence, MO

McKinney, TX

Raleigh, NC

Savannah-Chatham Metropolitan, GA

Springfield, MA

Sunnyvale, CA

West Palm Beach, FL

Trajectory Group 4 (N=71)

Akron, OH

Albuquerque, NM

Anaheim, CA

Aurora, IL

Bakersfield, CA

Boston, MA

Buffalo, NY

Chicago, IL

Chula Vista, CA

Clarksville, TN

Corona, CA

Downey, CA

Durham, NC

Escondido, CA

Fontana, CA

Fort Wayne, IN

Fremont, CA

Fullerton, CA

Garden Grove, CA

Hartford, CT

Hayward, CA

Huntsville, AL

Indianapolis, IN

Joliet, IL

Killeen, TX

Lakewood, CO

Little Rock, AR

Long Beach, CA

Los Angeles, CA

Madison, WI

Minneapolis, MN

New Haven, CT

New Orleans, LA

Oklahoma City, OK

Ontario, CA

Oxnard, CA

Pasadena, CA

Paterson, NJ

Peoria, IL

Pittsburgh, PA

Pomona, CA

Rialto, CA

Richmond, CA

Riverside, CA

Salem, OR

Salt Lake City, UT

San Bernardino, CA

San Diego, CA

San Francisco, CA

San Jose, CA

Santa Ana, CA

Santa Rosa, CA

Seattle, WA

South Bend, IN

Spokane, WA

Springfield, IL

St. Paul, MN

Syracuse, NY

Tacoma, WA

Toledo, OH

Tucson, AZ

Tulsa, OK

Vallejo, CA

Ventura, CA

Visalia, CA

Waterbury, CT

West Covina, CA

West Valley, UT

Wichita, KS

Worcester, MA

Yonkers, NY 

Trajectory Group 5 (N=2)

Inglewood, CA

Salinas, CA
19

 i This technique has been widely used in the classification of individuals according to their pattern of offending 

over time (Lacourse, Nagin, Tremblay, Vitaro et al., 2003; Piquero, 2008). (See Appendix B for a technical explanation 

of the trajectory procedure). In 2004, researchers began to apply this group-based trajectory method to model 

the criminal careers of geographic areas, such as street segments and census tracts, to capture communities’ 

trajectories across time and space (Griffiths and Chavez, 2004; Weisburd, Bushway, Lum, and Yang, 2004).

ii The National Gang Center was formerly called the National Youth Gang Center. iii For previous NGS publications covering relatively short time segments, see Egley, Howell, and Major (2004, 

2006); Howell (2006); Howell and Egley (2005); Howell and Gleason (1999); Howell, Egley, and Gleason (2002); 

and Howell, Moore, and Egley (2002).

iv The upturn in suburban counties from 2008 to 2009 is the result of a group of agencies newly reporting gang 

problems in their jurisdictions to the NYGS. However, based on the initial data submitted by these agencies, 

the gang problem appears relatively small in size (e.g., fewer than 20 gang members) and magnitude (all of the 

agencies with the exception of one reported zero gang homicides) in these areas.

v See Appendix A for further description of the two samples. Both samples included all cities above 50,000 in 

population and all suburban counties, and randomly selected agencies from smaller cities and rural counties. 

Thus, these analyses necessarily exclude agencies not participating in both samples.

vi Only two of the eligible cities were excluded from the analysis due to missing data for the entire time period. vii Reports from Tita and colleagues’ extensive program of gang research in Pittsburgh include Cohen, Cork, 

Engberg, and Tita, 1998; Cohen and Tita, 1999; Tita, 1999; Tita and Cohen, 2004; Tita, Cohen, and Engberg, 2005; 

Tita and Griffiths, 2005; and Tita and Ridgeway, 2007.

viii These are citizen-initiated emergency (911) calls to police. ix A census tract is considered to be a reasonable approximation of a “neighborhood” or a “community” (Griffiths 

and Chavez, 2004, p. 942).

x

 Tita and Cohen (1999) classified a homicide as gang-related if it involved some gang motivation (such as 

intergang disputes, initiation activities, or spontaneous drive-by killings) or if any participant was a gang member. 

Member-only homicides involved at least one gang member, but no gang motivation.

xi Places with the highest number of gang homicides typically report inordinately large numbers of gang members. 

Thus, their gang homicide rates (per 1,000 gang members) tend to be lower than those of other jurisdictions 

reporting some gang homicide among far fewer gang members. 

xii Includes “gangs” not traditionally considered “street gangs,” including Hells Angels and motorcycle outlaw 

gangs.

xiii This broad area encompasses both the East Region (Virginia, West Virginia, District of Columbia, Pennsylvania, 

Delaware, New Jersey, and New York) and the New England Region (Connecticut, Rhode Island, Massachusetts, 

Vermont, New Hampshire, and Maine).

xiv North Dakota, South Dakota, Nebraska, Kansas, Minnesota, Wisconsin, Iowa, Missouri, Michigan, Illinois, 

Indiana, Missouri, and Ohio.

xv California and Nevada.

xvi Texas, Oklahoma, Arkansas, Louisiana, Alabama, Georgia, Florida, South Carolina, Tennessee, North Carolina, 

Virginia, West Virginia, Maryland, and the District of Columbia.

NOTES
20

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This project was supported by Grant No. 2009-DG-BX-K114, awarded by the Bureau of Justice Assistance, 

and Grant No. 2007-JV-FX-0008, awarded by the Office of Juvenile Justice and Delinquency Prevention, 

Office of Justice Programs. The opinions, findings, and conclusions or recommendations expressed in this 

document are those of the authors and do not necessarily reflect the views of the U.S. Department of Justice.

The National Gang Center (NGC) is a collaborative effort between 

the Office of Justice Programs’ (OJP) Bureau of Justice Assistance (BJA) 

and the Office of Juvenile Justice and Delinquency Prevention (OJJDP).

This partnership works to provide professionals in the field of gangs 

with tools that can be used in a comprehensive range of strategies to 

respond to street gangs, from prevention and intervention to criminal 

justice strategies such as suppression, prosecution, and reentry.

James C. “Buddy” Howell is a senior research associate with the 

National Gang Center operated by the Institute for Intergovernmental 

Research® (IIR) in Tallahassee, Florida.

Arlen Egley is a senior research associate with the National Gang 

Center operated by the Institute for Intergovernmental Research® (IIR) 

in Tallahassee, Florida.

George Tita is an associate professor, Criminology, Law and Society at 

the University of California, Irvine, California.

Elizabeth Griffiths is an assistant professor, Department of Sociology, 

at Emory University, Atlanta, Georgia.

©2011 by the Institute for Intergovernmental Research® (IIR) on behalf of the National Gang Center. All Rights Reserved.