U.S. Department of Justice

Office of Justice Programs

Office of Juvenile Justice and Delinquency Prevention 

March 2002

A Message From OJJDP

The fact that our assessment of

current trends in juvenile offending

is based largely on arrest data reported to the Federal Bureau of Investigation (FBI) by local law enforcement

agencies raises a fundamental question about the capacity of such data

to provide an accurate and comprehensive picture of the myriad challenges that face today’s youth and

our society.

The information that this Bulletin offers on trends in juvenile violent offending over the past two decades,

however, comes from a different

source: the victims of those offenses.

Thus, unlike the data derived from

the FBI’s Uniform Crime Reports,

which drive traditional assessments,

the information provided by the National Crime Victimization Survey—

and featured in these pages—is not

limited to cases that come to the attention of local law enforcement officials, primarily through arrests.

By comparing the pictures of trends

in juvenile violent offending that these

diverse data sources provide, we can

begin to answer the critical question

posed above and to determine

whether our present understanding of

juvenile offending accurately reflects

the nature of those crimes—and not

merely the nature of its origins.

Accordingly, it is our hope that examining information from a variety of

sources about a variety of activities

related to juvenile offending will better

equip us to prevent and combat such

delinquent acts.

understanding of juvenile offending reflects

more the nature of crime or the peculiarities of the filters through which the problem is viewed.

Trends in Arrest Rates

From the FBI’s Uniform

Crime Reports

According to UCR data, on average, for the

period 1980 to 1998, the juvenile arrest

rate for serious violent crimes was 5 per

1,000 persons ages 12 to 17 in the residential population of the United States.1 Arrests decreased during the early 1980s and

then (with the exception of 1987) increased

steadily from 1984 until 1994 (figure 1).

They began to decrease in 1995 and continued to decrease through 1998.

Throughout the period 1980 to 1998, the

arrest rates for serious violent crimes

were much higher for male juveniles than

for female juveniles (figure 2). On average,

the arrest rate for male juveniles was 6.6

times that for female juveniles—8.6 per

1,000 and 1.3 per 1,000, respectively.2 The

overrepresentation of males in the juvenile

arrest rates for serious violent crimes

decreased over time. In 1980, the arrest

rate for male juveniles was 8.4 times the

rate for female juveniles. This imbalance

Trends in Juvenile Violent

Offending: An Analysis

of Victim Survey Data

James P. Lynch

Current understanding of juvenile offending nationally comes primarily from the arrest rates compiled by the Federal Bureau

of Investigation (FBI) for its annual Uniform Crime Reports (UCR) (Snyder and

Sickmund, 1999; Snyder, 2000). This Bulletin uses data from the National Crime

Victimization Survey (NCVS) to estimate

offending rates for juveniles from 1980

through 1998 from another perspective. 

The juvenile offending rates derived from

the NCVS data are examined by gender,

race, and type of crime. These trends are

compared with arrest rate trends based on

UCR data. Because victims have little information on crimes in which they do not

have face-to-face contact with offenders,

this analysis is restricted to violent offending. It is further restricted to relatively serious violent crimes—aggravated assault,

robbery, and forcible rape. Simple assaults

are excluded because this crime class includes a large number of very minor incidents that are infrequently reported to the

police and are arguably very different from

the incidents that are likely to be the object of police investigation. Unlike UCR

data, NCVS data are not limited to cases

that come to the attention of police or result in arrests. Comparing the pictures that

emerge from these different data sources

can help determine whether the current

Access OJJDP publications online at ojjdp.ncjrs.org

J. Robert Flores, Administrator October 2002
2

black juveniles in arrests for serious violent crimes decreased over time. In 1980,

the arrest rate for black juveniles was 6.1

times the rate for white juveniles, and in

1981, the ratio was 6.6. By 1998, it had

fallen to 3.9. Although this decrease was

pronounced, it was not consistent throughout the period. Much of the decrease occurred between 1996 and 1998.

declined steadily so that by 1998 the arrest

rate for male juveniles was only 4.5 times

that for female juveniles.

Throughout the period, the arrest rates

for serious violent crimes were much

higher for black juveniles than for white

juveniles (figure 3)—on average, 16.6 per

1,000 and 3.0 per 1,000, respectively. The

disproportionately larger involvement of

Limitations of Policeand Offender-Based

Data Sources

One must be cautious in using the foregoing arrest data to make statements about

the offender population and the offending

rate. UCR arrest data include a highly select group of offenders. Being arrested is

0

1

2

3

4

5

6

7

8

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Arrests (per 1,000 juveniles)

Year

Figure 1: Juvenile Arrest Rates for Serious Violent Crimes: 1980–98

Source: National Center for Juvenile Justice.

0

2

4

6

8

10

12

Arrests (per 1,000 juveniles)

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Year

Male Female

Figure 2: Juvenile Arrest Rates for Serious Violent Crimes, by Gender: 1980–98

Source: National Center for Juvenile Justice.
3

offenders are likely to be overrepresented

in UCR arrest data.

The picture of the offender population

emerging from self-report surveys of criminal behavior is also somewhat suspect.

The samples used in these surveys are

relatively small, and there is some concern that, because certain segments of

the population—specifically, minority

males—are not adequately captured in

these household surveys, their representation in the offending population will be

understated. Finally, self-report surveys

of offending are susceptible to response

errors in which respondents strategically

overstate or underreport their offending

behavior.

For these reasons, the descriptions of the

offending population that emerge from

these data sources are suspect. Therefore,

it is useful to examine the NCVS as another source of information on offenders and

offending rates. Although the NCVS has

limitations of its own that call the resulting

data into question, these limitations are

different from those affecting data gathered

from police reports and self-report surveys

of offending behavior. Consequently, the

NCVS can be used in concert with these

traditional sources to paint a more complete picture of the offender population. If

characteristics of the offender population

are similar across the three data sources,

then it is more likely that these statistical

systems are accurately describing offenders and offending trends. To the extent that

the data sources provide varying pictures

of juvenile offending, an attempt must be

made to understand why.

Trends in Offending

Rates From the

National Crime

Victimization Survey

The NCVS has existed since 1973 and can,

therefore, be used to assess offending

rates from that time until 1998 (the year

for which the most recent data are available). However, because the methodology

employed in the survey changed radically in 1992, the pre-1992 data used in this

analysis have been adjusted to make them

comparable to the post-1992 data (see

“Adjusting NCVS Data” on page 16).

Advantages and

Disadvantages of NCVS Data

The NCVS has some distinct advantages as

a source of data on offending behavior, at

least for serious violent offenses (Planty,

2000): 

◆ First, the NCVS should capture a greater

percentage of offending behavior than

can be captured in police records. A

large, nonrandom portion of offending

behavior is not reported to the police.

Some unknown proportion of offending

behavior is not reported in victim surveys, but it is certainly less than the

proportion not reported to the police.

◆ Second, the NCVS uses larger samples

than the National Longitudinal Survey of

Youth (NLSY) and other large-scale selfreport surveys of offending behavior.

This larger sample should increase the

reliability of the estimates of offending. 

imperfectly related to committing an offense. Fewer than 50 percent of all violent

crimes are reported to the police (Rennison, 2000). Even when crimes are reported,

many offenders are never apprehended

(Federal Bureau of Investigation, 1999).

Of those individuals identified by the police as offenders, many are not formally

charged. Even if police arrested every person who committed a crime, UCR data

would still be limited because almost 35

percent of all police departments in the

United States fail to completely report

their arrest data to the FBI (Jarvis and

Lynch, 1996; Maltz, 1999). This nonreporting of arrest data is not uniform across the

country. Larger jurisdictions report more

completely than smaller jurisdictions. This

filtering of cases by the police and policebased data systems can introduce substantial bias in the data.

For these reasons, using arrest rates to

approximate offending rates will undoubtedly produce low estimates of offending.

To the extent that attributes of offenders

(e.g., race, gender) affect the probability

of being arrested, UCR arrest data may

overrepresent “arrest-prone” groups of

offenders. In addition, local police departments’ different rates of reporting to the

FBI can also distort the picture of the offender population. If large urban police

departments that service areas with relatively large black populations, for example, report more completely than smaller

suburban departments that service predominately white communities, then black

Year

Arrests 

(per 1,000 juveniles)

0

5

10

15

20

25

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

White Black

Figure 3: Juvenile Arrest Rates for Serious Violent Crimes, by Race: 1980–98

Source: National Center for Juvenile Justice.
4

Computing Offending Rates With the NCVS

Victims could not report the age of the

offenders in only 2 percent of the incidents of violence reported in 1998. Nonresponse for gender and race of the

offender was only 0.2 percent and 0.9

percent, respectively. Because so few

data are missing (and because several

attempts to impute these data proved

unsuccessful), cases with missing information on age, race, or gender were

excluded from this analysis. This will

lead to a slight underestimate of the

offending rate.

Co-Offending

The problem of mixed age, race, and

gender groups of offenders is more serious than the missing data problem

because a much larger proportion of

crimes involve co-offending than missing data. From an information point of

view, it would be best to ask the respondent about each offender, but this

is burdensome for the respondent and

could increase nonresponse in the survey. The NCVS attempts to balance the

requirements of maintaining the quality

of information and limiting the burden

placed on respondents by asking about

groups of offenders collectively. So,

the survey includes questions about

whether all of the assailants were of

the same race or gender and what that

race or gender was. The problem with

reporting on aggregates of offenders is

that there will be mixed groups that cannot be allocated to a given race, gender,

or age group. If the group includes two

men and two women, all that can be

known from the NCVS data is that the

group contained both men and women.

Age. Because juvenile offending is the

focus of this study, it is important to accurately characterize offenders by age.

Moreover, the amount of adult and juvenile co-offending is substantial. For these

reasons, mixed-age groups could not

simply be omitted from the analysis. Instead, this Bulletin provides two estimates of juvenile offending. Offending

rates that included adult co-offending

assumed that all offenders in mixed-age

groups of offenders were juveniles. Offending rates that excluded adult cooffending assumed that all offenders in

mixed-age groups of offenders were

adults. The first of these estimates will

The National Crime Victimization Survey

(NCVS) is designed to produce victimization rates and incident rates for the

residential population of the United

States based on a sample from that

population:

◆ Victimization rates estimate the

number of people in a given population who have been victims. If two

people are robbed at gun point, this

would contribute two victimizations to

the victimization rate. If four people

were robbed, then four victimizations

would be added to the victimization

rate. The victimization rate is the sum

of the estimated number of victimizations divided by the estimate of the

population.

◆ Incident rates indicate the number

of crime events that have occurred.

The robbery with two victims would

contribute only one event to the incident rates because the two people were robbed in the same event.

To avoid the possibility of doublecounting an event with two victims,

any victimization is divided by the

number of victims in the incident,

because each victim has the potential to be in the sample and report

the event.1

Rates can be computed for the entire

population or for specific subgroups.2

Weighting Incident Rates To

Produce Offending Counts

Generating an offending rate requires an

estimate of the number of offending events

(that is, crimes committed), which is divided by the population being studied. A

given crime incident can have as many

offending acts as there are offenders involved. An incident involving three offenders, then, would contribute three offending acts to the offending rate because

three different people committed the criminal act. A crime perpetrated by only one

person would contribute one offense to

the offending rate.3 The number of offending acts is computed by multiplying the

incident weight by the number of offenders present during the criminal event.

Complications in Computing

Offending Rates With

the NCVS

Calculating the offending rate with the

NCVS is complicated by nonresponses

resulting in missing data, by the way in

which the survey asks about crimes involving co-offending, and by the “series

incident” procedure used to accommodate

high-volume repeat victimization. It is important, therefore, to describe how these

problems were taken into account in the

computation of the offending rate.

Missing Data

Nonresponse or missing data are a problem in any data set. Missing data are infrequent in the NCVS, compared with most

other data collections (e.g., the UCR or

National Woman’s Study). The NCVS has

a 95-percent response rate and very low

item nonresponse. In the case of information on offenders in violent crime incidents,

the amount of missing data is small.

1 The robbery with two victims would be divided by 2

(i.e., one event/two victims) and the result (0.5) would

be multiplied by the sample weight to obtain the contribution of this event to an incident count. The results

for all incidents would be summed across all respondents to get an incident count for the population. This

incident count would be divided by the weighted population count, as in the case of victimization rates, to

obtain an incident rate for the population.

2 A subgroup’s estimated number of victimizations is

developed by multiplying the subgroup’s reported number of victimizations by the subgroup’s sample weight.

The subgroup’s population is determined by multiplying

the number of respondents in the subgroup by the subgroup’s sample weight. The subgroup’s sample weight

is the inverse of the probability of being selected into

the sample. If 10 people are sampled from a subgroup

of 100, the probability of selecting a given person from

that subgroup is 1 over 10 or 10 percent. The inverse

of the probability (i.e., 1/0.1) is equal to 10. To produce

subgroup population estimates from their sample

counts, the counts from the sample would be multiplied

by the inverse of the probability of selection, or 10.

3 For a very small proportion of serious violent incidents,

the number of offenders reported by the respondent is

implausibly large. For the years 1993 to 1998, for example, victims reported between 1 and 96 offenders present during an incident. Moreover, approximately 1 percent of the serious violent incidents involved more than

10 offenders. Given the fact that these rare events can

contribute a great deal to the offending rate and that a

respondent cannot accurately count offenders beyond

a certain number, the computations of offending rates

presented in this Bulletin counted all events with 10 or

more offenders as having 10 offenders.
5

◆ Third, some reason exists to believe

that the response errors in the NCVS

may be less severe and better understood than those in self-report surveys

of offending. Respondents to self-report

surveys of offending may have substantial reasons for not responding accurately or truthfully—they may be concerned

about repercussions or may want to convey a certain image (Thornberry and

Krohn, 2000). The victim does not have

the same self-interest in reporting about

the attributes of offenders. To be sure,

there are a number of known response

errors in the NCVS that influence the

reporting of victimization events, and

incomplete reporting of crimes will 

lead to distortions in the description

of offenders (Biderman and Lynch,

1991); however, it seems likely that estimates of offending are affected less by

these sources of error than by the clear

self-interest for strategic response in

self-report surveys of offending.

◆ Finally, the NCVS includes a great deal of

detailed information on individual crime

events. In contrast, surveys of offending behavior are less concerned with

describing individual crime incidents

than with estimating the prevalence of

offending over a given period of time.

This information on the social context

of offending (e.g., where the crime

occurred, who was present, the number of offenders) can provide a description of offending that is simply not

available in existing surveys of offending behavior.3

The NCVS also has some clear limitations

for estimating offending rates:

◆ First, the NCVS asks very few questions

about the attributes of offenders. Respondents are asked about the age,

race, sex, and number of offenders and

about their relationship to the offender.

Surveys of offenders, obviously, can

provide much more detailed information about the offender. 

◆ Second, some researchers question

the ability of victims to provide reliable

information on offenders, even in violent crimes. Although the race and gender of offenders may be relatively easy

to identify, the same is not the case for

age—for example, it may be difficult to

make the distinction between a 21-yearold adult and a 17-year-old juvenile. 

◆ Third, design features of the NCVS may

also limit its utility for describing the

offender population accurately. The

fact that the NCVS only interviews

victims 12 years of age and older will

probably result in an underestimate of

the offending rate for juveniles, especially the offending rate for children

be too high and the other will be too low,

with a reasonable estimate of the juvenile offending rate being somewhere between the two. In this sense, the two estimates (including and excluding adult

co-offending) provide an interval within

which the actual juvenile offending rate

most likely falls.

Gender and race. A different approach

was taken to estimating gender- and

race-specific rates of juvenile offending.

Here, mixed-gender and mixed-race

groups that had a majority of one race or

one gender were treated as if all members of the group were of that race or

gender. So, if the group included one

male and three females, all offenders

were counted as female. When the respondent reported that no race or gender group was in the majority, the case

was omitted from the estimates. Approximately 7 percent of the violent incidents

fell into this category. Here again, this

estimation method will contribute to underestimating the juvenile offending rate.

There is no reason to believe, however,

that mixed-gender or mixed-race groups

occur more often in a particular race or

gender group and that omitting them

would lower the rates of one group relative to another. Hence, comparisons 

of the race- and gender-specific rates

should be appropriate. The strategy of

making multiple estimates was not followed for gender- and race-specific rates

because it would make presentation of

in series incidents is too high, but there

is also reason to believe that some of

these reports of high-volume repeat

victimization are accurate. Including series incidents as one crime probably

contributes to an underestimate of the

juvenile offending rate, but the amount

it contributes is unclear.4

In sum, the procedures used to take account of missing data, co-offending, and

series incidents all contribute to the underestimation of offending rates. The agespecific rates are least affected by the

procedural peculiarities of the NCVS because all mixed-group offending was included in these estimates. As a result,

for the age-specific rates, only missing

data and the handling of series incidents

contribute to the underestimate. The

race- and gender-specific rates are more

substantial underestimates because

some mixed-offending groups (those

perfectly balanced in terms of race and

gender) are omitted. This should not affect comparisons of rates across race

and gender groups.

the data too complex and the omission of

the mixed groups data did not make as

much difference in these rates as it did in

the age-specific rates.

Series Incidents

A series incident refers to a procedure

developed by the Census Bureau and

used in the NCVS that reduces the burden

of collecting information on high-volume

repeat victimization. When a respondent

reports he or she was victimized more

than five times in the past 6 months, when

these events are similar, and when the

respondent cannot report on the details

of each, then the interviewer is instructed

to note the number of incidents but only

collect detailed information on the most

recent event. Because the Bureau of

Justice Statistics, which sponsored the

NCVS, is concerned about the accuracy

of the information provided and, specifically, the number of events reported to

have occurred, it excludes these events

from annual rate estimates.

The estimates in this Bulletin include series incidents, but each one only as one

incident and not as the number of incidents that the respondent said occurred

in the series. Although series incidents

are a small part of annual victimization

rates, when they are weighted by the

number of individual incidents occurring

in them, they become more consequential. There is reason to believe that the

number of events reported as occurring

4 The vast majority of series incident victimizations

involve domestic violence and crimes at work (e.g.,

assaults and thefts that occur at work) (Dodge, 1987;

Lynch, Berbaum, and Planty, 1999). These events seldom involve juveniles. Approximately 12 percent of

series incidents take place at school, and these are

more likely to involve juveniles (Lynch, Berbaum, and

Planty, 1999).
6

younger than 12 who are most likely

to prey upon younger victims (Singer,

1981). However, because these younger

victims are often victimized by adult

caretakers (e.g., in sex offenses), interviewing these child victims could also

increase the proportion of older offenders recorded in the data.

◆ Fourth, the NCVS asks about only a

narrow range of crimes, and it can only

produce offending rates for those types

of crime. 

◆ Fifth, the NCVS cannot be used to produce prevalence estimates of offending

behavior because offenders cannot be

linked across crime incidents.

Readers should keep these strengths and

weaknesses in mind as they consider the

offending rates presented in the following

sections.

Trends in Offending Rates

Since 1980

The offending rates presented here are estimated with data from the NCVS. Overall

trends are reported along with separate

trends by gender and race. Gender and

race were chosen for separate consideration because these are the only attributes

of offenders included in both the UCR and

the NCVS.

Offending rates since 1980, by adult 

co-offending status. In the period 1980 to

1998, the juvenile offending rate for serious

violent crimes was, on average, somewhere

between 44 and 75 victimizations by juvenile offenders per 1,000 persons ages 12 to

17 in the U.S. population. The lower estimate excludes all co-offending with adults,

while the higher estimate includes all offenses in which there was co-offending

with adults (see discussion of co-offending

in “Computing Offending Rates With the

NCVS” on pages 4–5). Over the period

1980 to 1998, almost half the offending by

juveniles was done in concert with persons perceived by victims to be adults.4

From a high in 1981, the offending rate

(whether including or excluding adult cooffending) decreased until approximately

1988, when it began to increase sharply

and stayed relatively high until 1994. At

that point, it decreased sharply through

1998 (figure 4).

Including adult co-offending, the offending

rate for serious violent crimes was 80 per

1,000 in 1981. It dropped to 56 per 1,000

by 1987 but then rose sharply to 78 per

1,000 in 1988.5 It remained near this level

until 1992, when it rose to 89 per 1,000,

later peaking at 120 per 1,000 in 1993. In

1994, the rate began to decline until it

reached 51 per 1,000 in 1998.

The contours of the trend are reasonably

similar when co-offending with adults is

excluded. From 44 per 1,000 in 1981, the

juvenile offending rate (excluding adult

co-offending) for serious violent crimes

dropped to around 31 per 1,000 in 1982,

where it hovered through 1987. In 1988, it

increased to 36 per 1,000, then increased

sharply a few years later, reaching 91 per

1,000 in 1993. Thereafter, the rate declined

to 36 per 1,000 in 1998.

When adult co-offending incidents are examined separately, a very sharp increase in

adult co-offending between 1987 and 1988

is revealed (71 percent). This compares

with a 16-percent increase in juvenile-only

offending. The adult co-offending rate

dropped dramatically from 1991 to 1992

(a 38-percent decrease), while the juvenileonly rate increased. This suggests that

adult co-offending contributed disproportionately to the increases in total juvenile

offending in the late 1980s but did not

drive the decreases in total juvenile offending in the mid-1990s. While adult cooffending dropped dramatically between

1991 and 1992, this decrease was offset by

increases in juvenile-only offending. It was

not until later in the decade (approximately 1994) that juvenile-only offending began

to decrease markedly.

Offending rates since 1980, by gender.

Over the period 1980 to 1998, the average

offending rate for serious violent crimes

was 8 to 11 times higher (depending on

whether adult co-offending is excluded or

included) for male juveniles than female

juveniles. Excluding adult co-offending, the

average offending rates for male juveniles

and female juveniles were 68 per 1,000 and

0

20

40

60

80

100

120

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Year

Without adult co-offending With adult co-offending

Offenses (per 1,000 juveniles)

Figure 4: Juvenile Offending Rates for Serious Violent Crimes, by Adult Co-Offending Status: 1980–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Surveys: National Sample 1979–87 (computer file); National

Crime Surveys: National Sample 1986–91 (computer file); National Crime Victimization Survey 1992–98 (computer file).
7

8 per 1,000, respectively. Including adult

co-offending, the offending rate for male

juveniles was, on average, 122 per 1,000

compared with 11 per 1,000 for females.

Figure 5 shows the juvenile offending rates

for serious violent crimes by adult cooffending status and gender for the years

1980 to 1998.

Including adult co-offending, the offending

rate for male juveniles was high in 1981

(140 per 1,000) and declined unevenly to

a low of 88 per 1,000 in 1985. The rate increased slowly in 1986, dramatically increased to 135 per 1,000 in 1988, and

reached a high of 181 per 1,000 in 1993.

Thereafter, it declined steadily to a low of

83 per 1,000 in 1998. These trends are similar when co-offending with adults is excluded from the rates. 

The trends in the female offending rate

(either including or excluding adult cooffending) exhibit the same general movements from highs in the first half of the

1980s to lows in the second half of the

1980s to highs in the early 1990s and declines thereafter. These movements are

more erratic than the trends in male offending, in large part because the female

rate is so low in general.

The ratio of male-to-female offending rates

for serious violent crimes is greater when

adult co-offending is included than when it

is excluded. On average, during the period,

the total offending rate (including adult cooffending) for male juveniles was 11 times

that for female juveniles. When adult cooffending is excluded, the ratio decreases

to 8. This suggests that male juveniles are

more likely than female juveniles to engage

in serious violent co-offending with adults.

The overrepresentation of males in serious

violent offending decreased over time. 

Excluding adult co-offending, from 1980 to

1986, male juveniles, on average, were engaged in serious violent offending at 16

times the rate of female juveniles. In the

period 1993 to 1998, this ratio decreased

to 8. This decrease resulted more from 

an increase in the offending rate of female

juveniles than a decrease in the offending

rate of male juveniles.

Offending rates since 1980, by race.

Over the period 1980 to 1998, the average

offending rate for serious violent crimes

was 3.4 to 4.1 times higher (depending on

whether adult co-offending is excluded or

included) for black juveniles than white

0

40

80

120

160

200

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Offenses 

(per 1,000 juveniles)

Male Juvenile Offending

0

5

10

15

20

25

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Year

Without adult co-offending With adult co-offending

Female Juvenile Offending

Offenses 

(per 1,000 juveniles)

Year

Figure 5: Juvenile Offending Rates for Serious Violent Crimes, by Adult Co-Offending Status and Gender:

1980–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Surveys: National Sample 1979–87 (computer file); National

Crime Surveys: National Sample 1986–91 (computer file); National Crime Victimization Survey 1992–98 (computer file).
8

juveniles. The average offending rate for

black juveniles was between 96 per 1,000

(excluding adult co-offending) and 167

per 1,000 (including adult co-offending)

compared with between 28 and 41 per

1,000, respectively, for white juveniles.

Adult co-offending was a more prominent

feature of serious violent offending for

black juveniles than for white juveniles.

On average, over the period 1980 to 1998,

the ratio of adult co-offending to total juvenile offending was 0.31 for whites (approximately 1 instance of adult co-offending

for every 3 instances of juvenile offending)

and 0.43 for blacks (more than 2 instances

of adult co-offending for every 5 instances

of juvenile offending).

Adult co-offending accounted for a disproportionate amount of the increase in serious violent offending for black juveniles 

in the late 1980s (figure 6). Rates of adult

co-offending for blacks increased by 60

percent between 1986 and 1987 and by 37

percent from 1988 to 1989. The juvenileonly offending rates for blacks during this

period increased much less (increasing 15

percent from 1986 to 1987 and decreasing

2 percent between 1988 and 1989). Later,

between 1991 and 1993, this trend was reversed as the increases in juvenile-only

offending were larger than the increases in

adult co-offending.6

Trends in Offending Rates

Since 1993

The longer term trends reported in the

previous section were limited to broad

categories of gender and race because

the adjustments that must be applied to

pre-1992 NCVS data are more reliable for

larger groups than smaller ones. In the

period 1993 to 1998, no adjustments need

to be applied, so it is possible to examine

more specific demographic and offense

categories. Moreover, because some of

the more pronounced decreases in arrests and offending occurred in this period, a more detailed examination may

be enlightening.

0

50

100

150

200

250

300

Black Juvenile Offending

Offenses 

(per 1,000 juveniles)

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

0

10

20

30

40

60

50

White Juvenile Offending

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Without adult co-offending With adult co-offending

Offenses 

(per 1,000 juveniles)

Year

Year

Figure 6: Juvenile Offending Rates for Serious Violent Crimes, by Adult Co-Offending Status and

Race: 1980–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Surveys: National Sample 1979–87 (computer file); National

Crime Surveys: National Sample 1986–91 (computer file); National Crime Victimization Survey 1992–98 (computer file).
9

Offending rates since 1993, by specific

crime category. The decrease in serious

violent offending between 1993 and 1998

was greatest for robbery and, in some

cases, less for aggravated assault (figure

7).7 In 1993, the total juvenile offending

rate (including adult co-offending) for robbery was 46.6 per 1,000. This fell to 14.8

per 1,000 by 1998, a decrease of 68 percent. When adult co-offending is excluded,

the rate decreased from 30.4 per 1,000 in

1993 to 10.7 per 1,000 in 1998, a decrease

of 64 percent. The total juvenile offending

rate (including adult co-offending) for aggravated assault decreased from 67.4 per

1,000 in 1993 to 30.9 per 1,000 in 1998, or

54 percent. When adult co-offending is excluded, the rate decreased from 40.9 to

14.7, or 64 percent. Therefore, for both

robbery and aggravated assault, with

adult co-offending included or excluded,

the rate of serious juvenile violence in

1998 was just one-third of its 1993 level.

These declines in offending rates for robbery and aggravated assault are greater

than the corresponding declines in the

juvenile arrest rates for robbery (41 percent) and aggravated assault (16 percent).

An Important Distinction

When interpreting the rates presented

in this Bulletin, it is important to appreciate the difference between offending rates and offender rates. An

offending rate estimates the number

of offenses committed by a given population. The offending rate is often referred to as the incidence rate. An offender rate estimates the number of

persons in a given population who

have committed one or more crimes.

The offender rate is often referred to

as the prevalence rate.

The difference between these rates 

is that prevalence rates do not take

account of repeated offending by the

same person, whereas incidence rates

do. Once a person has committed one

offense, that person is counted in the

numerator of the offender rate and

subsequent offending by that person

will not affect the rate. In contrast, the

numerator of the offending rate will

increase whenever a new offense is

committed by a member of the at-risk

population. One of the advantages of

a prevalence rate is that it cannot exceed 1.0 and provides an easily interpretable indicator of how many of the

persons in a given group have offended in a given period of time. With a

prevalence rate, one can say, for example, that 40 percent of male juveniles have offended in a year. An incidence rate, on the other hand, can

exceed 1.0 if some members of the

at-risk population commit more than

one offense during the period. Incidence rates indicate the relative involvement of groups in offending or

the relative contribution of a group to

total offending while taking into account the size of the group. With an

incidence rate, it is possible to say,

for example, that males are twice as

likely to engage in offending behavior

as females, but impossible to say

what proportion of each group engages in offending behavior.

Most of the indicators used in criminal

justice are incidence rates, largely because it is difficult to identify repeat

offenders or repeat victims, and doing

so is essential for estimating prevalence rates. So the UCR crime rates

published annually by the FBI are incidence rates, as are the victimization

rates published by the Bureau of Justice Statistics. It is important to keep

in mind the difference between incidence and prevalence rates.

0

10

20

30

40

50

0

10

20

30

40

50

60

70

80

Robbery

Aggravated Assault

Year

1993 1994 1995 1996 1997 1998

1993 1994 1995 1996 1997 1998

Offenses 

(per 1,000 juveniles)

With adult 

co-offending

Without adult 

co-offending

Offenses 

(per 1,000 juveniles)

Year

Figure 7: Juvenile Offending Rates for Robbery and Aggravated

Assault, by Adult Co-Offending Status: 1993–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Victimization

Survey 1992–98 (computer file).
10

Offending rates since 1993, by race and

crime category. The decrease in overall

serious violent offending was greater for

black juveniles than for white juveniles

from 1993 to 1998, and this pattern was

replicated for both robbery and aggravated

assault (figure 8). For robbery, including

adult co-offending, the offending rate for

white juveniles decreased 46 percent

(45 percent when adult co-offending is excluded) and the offending rate for black

juveniles decreased 76 percent (77 percent excluding adult co-offending). The

decrease in the offending rate (including

adult co-offending) for white juveniles

who committed aggravated assault was

49 percent (50 percent excluding adult

co-offending) compared with 70 percent

(79 percent excluding adult co-offending)

for black juveniles.

Trends in co-offending since 1993. It is

possible, using NCVS data, to examine the

contribution of co-offending to the total

juvenile offending rate for serious violent

crimes. Throughout the period 1993 to

1998, the average annual juvenile offending rate was 87 offenses per 1,000. Lone

offending accounted for 18 offenses per

1,000, co-offending with other juveniles

accounted for 42 per 1,000, and cooffending with adults accounted for 27

per 1,000. Overall, three-fourths of juvenile

offending was co-offending, and more than

0

5

10

15

20

25

30

35

40

1993 1994 1995 1996 1997 1998

0

20

40

60

80

100

120

140

1993 1994 1995 1996 1997 1998

Aggravated assault (excluding adult co-offending)

Aggravated assault (including adult co-offending)

Robbery (excluding adult co-offending)

Robbery (including adult co-offending)

White Juvenile Offending

Black Juvenile Offending

Offenses (per 1,000 juveniles)

Year

Offenses (per 1,000 juveniles)

Year

Figure 8: Juvenile Offending Rates for Robbery and Aggravated Assault, by Adult Co-Offending Status

and Race: 1993–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Victimization Survey 1992–98 (computer file).
11

one-third of the co-offending was with

adults.

All categories—lone offending, co-offending

with juveniles, and co-offending with

adults—of the juvenile offending rate for

serious violent crimes decreased during

1993–98 (figure 9). The total juvenile offending rate for serious violent crimes decreased 57 percent, from 119 per 1,000 to

51 per 1,000. The decrease in offending

rates between 1993 and 1998 was greater

for co-offending than for lone offending.

The offending rate for lone offenders who

committed serious violent crimes decreased by 42 percent over the period,

from 24 per 1,000 to 14 per 1,000. The cooffending rate (including both juvenile and

adult co-offenders) declined 61 percent,

from 96 to 37 per 1,000. The juvenile

co-offending rate decreased more than the

adult co-offending rate (67 percent and 47

percent, respectively). 

Co-offending is somewhat greater among

male juveniles than female juveniles (table

1). On average, throughout the period 1993

to 1998, approximately 78 percent of the

male juvenile offending rate for serious violent crimes involved co-offending compared with 70 percent for female juveniles.

Co-offending for male juveniles was evenly

split between adult co-offending (42 percent

of all incidents) and juvenile co-offending

(35 percent of all incidents). However, for

female juveniles, a greater proportion of

all serious violent crimes involved juvenile

co-offenders (43 percent of all incidents)

than adult co-offenders (27 percent of all

incidents).

Decreases in serious violent offending from

1993 to 1998 were greater for female juveniles (68 percent) than for male juveniles

(55 percent). The decreases in lone offending and adult co-offending were slightly

greater for female juveniles (46 and 61 percent respectively) than male juveniles (42

and 59 percent, respectively).8 The largest

differences between the genders occurred

in co-offending with other juveniles, where

the decrease for male juveniles was 62 percent compared with a 92-percent decrease

for female juveniles. Figure 10 shows the

1993–98 rates of lone offending, juvenile

co-offending, and adult co-offending for

male and female juveniles.

Between 1993 and 1998, lone offending represented a much higher proportion of the

offending rate for white juveniles than for

black juveniles (table 2). Thirty-one percent

of the white juvenile offending rate for serious violent crimes involved lone offending,

37 percent involved co-offending with adults,

and 32 percent involved co-offending with

juveniles. In contrast, only 20 percent of

the black juvenile offending rate for serious violent crimes involved lone offending, 39 percent involved co-offending

with adults, and 41 percent involved cooffending with juveniles.

Between 1993 and 1998, the rate of serious

violent offending decreased 72 percent for

black juveniles and 40 percent for white

juveniles. Lone offending dropped by about

the same proportion for both races (42

percent for black juveniles and 43 percent

for white juveniles). Co-offending with

adults decreased more for black juveniles

than for white juveniles (63 percent and 50

percent, respectively). The largest difference was for co-offending with juveniles,

which decreased 90 percent for black juveniles and 29 percent for white juveniles.

Figure 11 shows the 1993–98 rates of lone

offending, co-offending with juveniles, and

co-offending with adults for white and

black juveniles.

In sum, much of the serious violent offending by juveniles is done in groups, and juveniles are as likely to co-offend with an

adult as with other juveniles (based on

victims’ perceptions of offender age). Males

engage in co-offending more than females,

and blacks more than whites. Between

1993 and 1998, rates of co-offending have

decreased faster than rates of lone offending. These decreases in co-offending have

been more pronounced for blacks than for

whites.

0

10

20

30

40

50

60

70

80

Offenses (per 1,000 juveniles)

1993 1994 1995 1996 1997 1998

Year

Lone offending Co-offending with juveniles Co-offending with adults

Figure 9: Juvenile Offending Rates for Serious Violent Crimes, by

Co-Offending Status: 1993–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Victimization

Survey 1992–98 (computer file).

Table 1: Average Juvenile Offending Rates for Serious Violent Crimes,

by Gender and Co-Offending Status: 1993–98

Offending Rate (per 1,000 juveniles)

Committed Committed Committed All

Gender Alone With Adult With Juvenile Incidents

Male 30.3 55.4 47.7 133.3

Female 4.7 4.3 6.8 15.8
12

Comparing UCR and

NCVS Estimates of

Offending Rates

As noted previously, UCR data indicate that

the average annual juvenile arrest rate for

serious violent crimes during 1980–98 was

5 per 1,000 persons ages 12 to 17. NCVS

data indicate that, depending on whether

adult co-offending is excluded or included,

the juvenile offending rate for the same

crimes during the same period was 9 to 15

times the juvenile arrest rate (44 per 1,000

excluding adult co-offending and 75 per

1,000 including adult co-offending). This is

not unreasonable, considering that only

20 percent of the violent crimes by juveniles reported in victim surveys are reported to the police and that, of those

crimes reported to the police, approximately 50 percent lead to an arrest.

The broad trends in the UCR arrest data

and NCVS offending data are similar. Both

show decreases in the early 1980s followed

by an increase later in the decade, with

continued high rates until the mid-1990s,

when rates dropped dramatically (figure 1

and figure 12). Arrest rates reached a low

point in 1987 but increased steadily thereafter until 1994, when they began to drop.

Offending rates reached a low point in

1987 and then increased in 1988. These

higher rates persisted until 1994, when

they began to trend downward. 

The increases observed in the mid-1980s

were similar for offending rates and arrest

rates, but the decreases in the 1990s were

greater for offending rates than for arrest

rates. Between 1987 and 1993, the juvenile

arrest rate increased about 70 percent,

while the juvenile offending rate increased

between 114 percent (including adult

co-offending) and 195 percent (excluding

adult co-offending). Regardless of the assumptions that are made about adult cooffending, the increase in the offending

rate was greater than the increase in the

arrest rate. Similarly, the juvenile arrest

rate for serious violent crimes declined

27 percent from 1993 to 1998, while the

juvenile offending rate for serious violent

crimes declined between 57 percent (including adult co-offending) and 60 percent

(excluding adult co-offending) during the

same period. The increases and decreases

in the offending rate during 1980–98 were

much greater than the increases and decreases in the arrest rate.

Female Juvenile Offending

Offenses (per 1,000 juveniles)

1993 1994 1995 1996 1997 1998

Year

Lone Offending Co-offending with juveniles Co-offending with adults

Offenses (per 1,000 juveniles)

Year

0

10

20

30

40

50

60

70

80

90

Male Juvenile Offending

1993 1994 1995 1996 1997 1998

0

2

4

6

8

10

12

14

16

18

Figure 10: Juvenile Offending Rates for Serious Violent Crimes,

by Gender and Co-Offending Status: 1993–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Victimization

Survey 1992–98 (computer file).
13

Comparison by Gender

The data on both arrests and offending

showed higher rates of serious violent

offending for male juveniles than female

juveniles. The overrepresentation of males

was greater in the data on offending than

in the arrest data. This means that, given

their offending rates, male juveniles were

underrepresented and female juveniles

were overrepresented in arrest data. The

disproportionality of male offending decreased over time but more so in arrest

data than in offending data.

The ratio of male juveniles to female juveniles was lower in the arrest data than in

the offending data. For serious violent

crimes (i.e., forcible rape, robbery, and

aggravated assault), the average ratio of

male juveniles to female juveniles was

6.8 in the arrest data but ranged between

9 (excluding adult co-offending) and

11.5 (including adult co-offending) in the

offending data. This discrepancy may be

due to the fact that more crimes involving intimates (e.g., siblings, dating couples) are reported in the NCVS than in

police data systems. There may be more

male offenders in these crimes than in

other types of violent crimes, resulting in

a higher ratio of male to female offenders.

Domestic violence, for example, is more

often committed by males than females.

Between 1980 and 1998, the male-female

ratio for juvenile arrest rates for serious

violent crimes decreased from 8.3 to 4.5

(figure 13). The male-female ratio for juvenile offending rates for serious violent

crimes has also generally decreased, but

not as consistently and not as much as the

arrest rate ratio. The male-female ratio for

offending rates (with adult co-offending

included) decreased from a high of 22 in

1981 to 10.5 in 1998 (with a low of 7.3 in

1993). When adult co-offending is excluded, the ratio was 16.8 in 1981 and 10.4 in

1998 (with a low of 4.9 in 1993). Although

this seems broadly consistent with the

arrest data, the male-female ratio in offending has fluctuated throughout the period.

Indeed, this ratio increased from 1996 to

1998 in the offending data, while it continued to decline in the arrest data.

One of the factors contributing to the decline in the overrepresentation of males

in juvenile arrest rates for serious violent

crimes has been the steady increase in the

arrest rates for female juveniles since 1980.

Between 1980 and 1998, the female juvenile

arrest rate for serious violent crimes increased 89 percent, from 0.9 per 1,000 to

1.7 per 1,000 (figure 2). The arrest rate for

0

2

4

6

8

10

12

14

16

18

20

0

20

40

60

80

100

120

140

Black Juvenile Offending

Offenses (per 1,000 juveniles)

1993 1994 1995 1996 1997 1998

White Juvenile Offending

Year

1993 1994 1995 1996 1997 1998

Lone Offending Co-offending with juveniles Co-offending with adults

Offenses (per 1,000 juveniles)

Year

Figure 11: Juvenile Offending Rates for Serious Violent Crimes,

by Race and Co-Offending Status: 1993–98

Sources: U.S. Department of Justice, Bureau of Justice Statistics, National Crime Victimization

Survey 1992–98 (computer file).

Table 2: Average Juvenile Offending Rates for Serious Violent Crimes,

by Race and Co-Offending Status: 1993–98

Offending Rate (per 1,000 juveniles)

Committed Committed Committed All

Race Alone With Adult With Juvenile Incidents

White 12.0 14.4 12.2 38.6

Black 34.9 68.5 71.6 174.9
14

male juveniles increased only 2 percent

during the same period. Moreover, arrest

rates for male juveniles fluctuated during

this period, but arrest rates for female juveniles increased consistently throughout

the 19 years. In contrast, female offending

rates varied much more over time and did

not show the steady increase found in the

female arrest rates (figure 5).

Comparison by Race

The data on both offending and arrests

showed that compared with white juveniles, black juveniles had much higher

0

20

40

60

80

100

120

140

Juvenile offending Juvenile arrests*

(excluding adult co-offending) 

Juvenile offending

(including adult co-offending)

Year

Arrests/Offenses 

(per 1,000 juveniles)

1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Figure 12: Juvenile Arrest and Offending Rates for Serious Violent Crimes, by Adult Co-Offending Status:

1980–98

* Due to the difference in scale between the arrest and offending rates presented in this figure, the rate for juvenile arrests appears relatively flat.

Figure 1 presents this juvenile arrest data using a different scale which better shows the fluctuation in juvenile arrest rates during this period.

Sources: National Center for Juvenile Justice. U.S. Department of Justice, Bureau of Justice Statistics, National Crime Surveys: National Sample

1979–87 (computer file); National Crime Surveys: National Sample 1986–91 (computer file); National Crime Victimization Survey 1992–98

(computer file).

0

4

8

12

16

20

24

1980 1981 1982 1983 1984 1985 1986 1987 1988 1990 1991 1992 1993 1994 1995 1996 1997 1998

Offending rates Arrest rates

(excluding adult co-offending)

Offending rates 

(including adult co-offending)

Year

Male-Female Ratio

1989

Figure 13: Male-Female Ratios for Juvenile Arrest and Offending Rates for Serious Violent Crimes, by Adult

Co-Offending Status: 1980–98

Sources: National Center for Juvenile Justice. U.S. Department of Justice, Bureau of Justice Statistics, National Crime Surveys: National Sample

1979–87 (computer file); National Crime Surveys: National Sample 1986–91 (computer file); National Crime Victimization Survey 1992–98

(computer file).
15

rates of involvement in serious violent

crime. This disproportionality was greater

in arrest rates than in offending rates.

However, it decreased over time in both

the arrest data and the offending data.

Much of the overall decrease in the disproportionality of serious violent offending by black juveniles was the result of

the large decrease in offending by blacks

for these crimes that occurred after 1993.

During 1980–98, the average arrest rate for

serious violent crimes was 5.7 times higher

for black juveniles than for white juveniles.

The black-white ratio for offending rates

for serious violent crimes ranged from

4.1 (including adult co-offending) to 3.4

(excluding adult co-offending). Although

blacks are overrepresented in both the

offending data and the arrest data for

1980–98, the overrepresentation is greater in the arrest data.

Over time, the black-white arrest rate

ratio declined from a high of 6.9 in 1983 to

3.9 in 1998, or 43 percent (figure 14). The

comparable offending ratio (including

adult co-offending) decreased from a high

of 6.1 in 1992 to 2.4 in 1998, or 61 percent.

When adult co-offending is excluded from

the offending rates, the ratio decreased

from a high of 5.2 in 1993 to a low of 1.9

for 1998, or 63 percent.

In the period 1992–98, the black-white

arrest ratio was quite similar to the blackwhite offending ratio. On average during

this period, the black arrest rate was 4.9

times that of whites. The black offending

rate was 4.2 times that of whites when

adult co-offending is excluded and 4.6

times that of whites when adult cooffending is included.

The decrease in the overrepresentation of

blacks in juvenile arrest rates for serious

violent crimes resulted in part from the

steady increase in arrest rates for white

juveniles since the early 1980s. The white

juvenile arrest rate for serious violent

crimes increased from 2.3 in 1980 to 4.2 in

1994 (figure 3), an increase of 83 percent.

This rate only began to decrease noticeably in 1996. In contrast, the black juvenile arrest rate for serious violent crimes

increased 64 percent during 1980–94, and,

beginning in 1994, it decreased more

sharply than the arrest rate for white juveniles. Looking at offending rates, the

decrease in the racial disproportionality

has resulted from decreases in black offending since 1990, not increases in white

offending.

Conclusion

Examining serious violent offending

through data gathered from victims

provides a picture that is both similar to

and different from that emerging from police arrest data. Not surprisingly, the volume of offending is much greater in the

NCVS data than is indicated in the UCR

arrest data. Depending on whether adult

co-offending is excluded or included, offending rate estimates from the NCVS data

are 9 to 15 times greater than the arrest

rate estimate from the UCR data. Both

sources of data show race and gender disproportionality in serious violent offending. Male juveniles offend at much higher

rates than female juveniles. Black juveniles offend at much greater rates than

white juveniles. The amount of gender

disproportionality, however, is greater in

the NCVS data than the UCR data, while

the racial disproportionality is greater in

the UCR data than the NCVS data. In other

words, victims indicate that there are

more male offenders (relative to female

offenders) and more white offenders (relative to black offenders) than appear in

police records.

Arrest rates

1

2

3

4

5

6

7

8

Black-White Ratio

1980 1981 1982

Offending rates 

(including adult co-offending)

Offending rates 

(excluding adult co-offending)

1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998

Year

Figure 14: Black-White Ratios for Juvenile Arrest and Offending Rates for Serious Violent Crimes,

by Adult Co-Offending Status: 1980–98

Sources: National Center for Juvenile Justice. U.S. Department of Justice, Bureau of Justice Statistics, National Crime Surveys: National Sample

1979–87 (computer file); National Crime Surveys: National Sample 1986–91 (computer file); National Crime Victimization Survey 1992–98

(computer file).
16

The trends in serious violent offending for

juveniles are broadly similar in the two

data sources. Both show decreases in serious violent offending until about 1986–87

and increases thereafter until around 1994,

when sharp decreases began and continued until 1998. Both race and gender disproportionality declined between 1980 and

1998 in both the UCR and NCVS data, as

the overrepresentation of male offenders

and the overrepresentation of black offenders decreased.

This examination of offending using NCVS

data confirms the general picture of offending derived from UCR arrest data. At

the same time, the greater racial disproportionality and the lower gender disproportionality found in the arrest data raise

some questions. It is tempting to infer that

police policy is the likely cause of these differences, specifically, that the police tend

to arrest black offenders more often than

white offenders or female offenders more

often than male offenders. However, recent

research (Pope and Snyder, in press) finds

no support for these contentions, at least

as they apply to serious violent crimes.

Adjusting NCVS Data

As noted in the text, the methodology employed in the National Crime Victimization Survey (NCVS) was changed radically in 1992. As a result, data from the pre-1992 period,

when the survey was known as the National Crime Surveys

(NCS), must be adjusted to make them comparable to the

more recent data. An adjustment of the data is possible because the old NCS and new (NCVS) designs were run in

parallel for 18 months. Data from this overlap period can be

used to compute the ratio of estimates from the post-1992

and pre-1992 designs. This ratio, in turn, can be used to adjust all the pre-1992 data to make them comparable to the

post-1992 data (Kindermann, Lynch, and Cantor, 1997;

Rand, Lynch, and Cantor, 1997; Lynch and Cantor, 1996).

The Bureau of Justice Statistics (BJS) has produced a ratio

adjustment for major crime classes. BJS cautions, however,

that this adjustment factor may not be suitable for adjusting

trends for subpopulations (such as juveniles) or specific estimates other than victimization rates. Consequently, adjustment factors for offender trends have been specifically developed for the analysis presented in this Bulletin.

These adjustment factors were produced using the same

methodology employed by Lynch and Cantor (1996) to determine the adjustments BJS used for gross victimization

trends. Specifically, offending rates were estimated using the

NCS and the NCVS data from the 1992 overlap. Significance tests were performed on the differences between the

rate estimates from the old and new designs. When significant differences were found, further tests were employed for

specific subpopulations. If, for example, the rates from the

NCVS were significantly different from the NCS for both

males and females, the significance of this difference was

tested to determine whether specific ratio adjustments

should be applied for each gender. Whenever significant

differences between the designs were found, adjustment

ratios were produced and applied to each subgroup. If these

differences were not significant, then the same adjustment

ratio was applied to all subgroups. The following are the adjustment ratios used in this Bulletin for offending rates overall, by gender, and by race.

Overall. The adjustment ratios for overall juvenile offending

including adult co-offending are as follows: rape, not significant (ns); robbery, ns; aggravated assault, ns; simple assault, 2.02; total violence, 1.58. The adjustment ratios for

juvenile offending excluding adult co-offending are as follows: rape, 1.65; robbery, ns; aggravated assault, 0.91;

simple assault, 1.74; total violence, 1.29.

By gender. The adjustment ratios for male juvenile offending

including adult co-offending are as follows: rape, 3.05; robbery, ns; aggravated assault, ns; simple assault, 1.42; total

violence, 1.41. The adjustment ratios for male juvenile offending excluding adult co-offending are as follows: rape, ns; robbery, ns; aggravated assault, ns; simple assault, 1.69; total

violence, 1.68. The adjustment ratios for female juvenile offending including adult co-offending are as follows: rape, ns;

robbery, ns; aggravated assault, ns; simple assault, 1.42; total

violence, 1.41. The adjustment ratios for female juvenile offending excluding adult co-offending are as follows: rape, ns;

robbery, ns; aggravated assault, ns; simple assault, 1.69; total

violence, 1.68.

By race. The adjustment ratios for white juvenile offending

including adult co-offending are as follows: rape, ns; robbery,

ns; aggravated assault, 1.48; simple assault, 1.79; total violence, 1.59. The adjustment ratios for white juvenile offending

excluding adult co-offending are as follows: rape, ns; robbery,

ns; aggravated assault, 1.90; simple assault, 1.68; total violence, 1.53. The adjustment ratios for black juvenile offending

including adult co-offending are as follows: rape, ns; robbery,

ns; aggravated assault, 0.63; simple assault, 1.99; total violence, 1.11. The adjustment ratios for black juvenile offending

excluding adult co-offending are as follows: rape, ns; robbery,

ns; aggravated assault, 0.59; simple assault, 2.06; total violence, 1.53. The adjustment ratios for other-race juvenile offending including adult co-offending are as follows: rape, ns;

robbery, ns; aggravated assault, 2.29; simple assault, 3.75;

total violence, 2.26. The adjustment ratios for other-race juvenile offending excluding adult co-offending are as follows:

rape, ns; robbery, ns; aggravated assault, 1.0; simple assault,

3.55; total violence, 3.18.

Although this adjustment procedure is useful, it must be used

with caution. The 18-month overlap period does not provide

many data for estimating adjustment ratios. The NCVS sample was not expanded during this period. Half the usual

NCVS sample completed the pre-1992 instrument and half

the post-1992 instrument. As a result, the reliability of the estimates from the overlap period is less than that of the NCVS

generally. This means that the adjustment ratios are likely to

be unstable for smaller population subgroups and rare offenses. Moreover, the accuracy of the adjustment ratios is likely to

decrease the farther back in time one goes from the overlap

period. For these reasons, this Bulletin presents trends only

back to 1980, and these trends are limited to large classes

of violent crime and major population groups. More detailed

trends were produced for the post-1992 period (see “Trends

in Offending Rates Since 1993” on pages 8–11), when a consistent design was used for the full NCVS sample.
17

Other explanations must be considered.

One factor may be differential reporting of

crimes by victims. For example, if victims

of crime by black offenders are more likely

to report their victimization to the police,

then the arrest rate for black offenders will

be higher even if the police treat every

case about equally. Other factors may be

differences in the scope, definitions, and

procedures used in police record systems

and victim surveys. The UCR arrest rates,

for example, include arrests for events that

are not asked about in the NCVS, such as

commercial robbery, which in the UCR

arrest data is not separated from noncommercial robbery and thus cannot be removed from the dataset to allow equal

comparison with the NCVS data. If these

events involve black offenders more than

white offenders, then this could account

for the greater racial disproportionality in

the arrest data relative to the offending

data. Similarly, the fact that larger urban

places (which have disproportionately

large black populations) report more reliably than smaller places in the UCR may

lead to the overrepresentation of black juveniles in the UCR arrest data. If analysts

adjusted the UCR arrest data to take the

missing information into account more

systematically, the differences between

the police and victim survey data in race

and gender disproportionality might

disappear. 

All of these explanations—and others—

must be pursued to understand the apparently discrepant pictures of offenders

emerging from the UCR and the NCVS. The

good news is that most of these alternative

explanations for the observed differences

can be examined with the UCR and NCVS

data. Although beyond the scope of this

analysis, it is possible, for example, to develop and apply adjustments in the UCR to

account for the overrepresentation of large

population places. Then this explanation

for black overrepresentation in the UCR

data would be eliminated.

Finally, this examination of victim data offers a view of co-offending that is not often

obtained (or obtainable) from police data.

The majority of juvenile violent offending

is done in groups. About one-third of this

group offending involves adults. Male juveniles are more disposed to group offending

than female juveniles, and black juveniles

much more than white juveniles. The declines in the juvenile offending rates for

serious violent crimes between 1994 and

1998 were greatest for juvenile co-offending,

especially for blacks. It is unclear why the

drop in juvenile co-offending was so steep

for blacks compared with whites.9 Possible

explanations for this dramatic decrease in

violent co-offending among black juveniles

should be explored empirically to enhance the understanding of the recent

drop in overall crime, with particular attention to the disparate declines in lone

and group offending.

Endnotes

1. The numerator for the arrest rates presented in this Bulletin is arrested juveniles

between the ages of 10 and 17. The denominator for the arrest rates is all juveniles between ages 12 and 17. This denominator was used to be consistent with the

denominator for the offending rates from

the NCVS. Because there are relatively few

arrested persons younger than 12 in the

UCR data, including them in the numerator (but not the denominator) of the rate

will not distort the arrest rate by much.

The UCR arrest rates used in this Bulletin

will be slightly higher than they should be. 

2. For ease of reading and to maintain

consistency within the Bulletin, rounded

numbers are used in calculations and presented in the text. The methodology used

to calculate the trends presented in the

Bulletin is described in “Computing Offending Rates With the NCVS” (see pages

4–5). See also “Adjusting NCVS Data”

(page 16).

3. The Survey of Inmates in State and Federal Facilities includes information on the

crime event that brought the inmate to

prison, but the respondents are largely

adults.

4. The imprecision of this statement

comes, in part, from the difficulty of judging the age of offenders in the course of

a criminal event and the fact that most

adult co-offenders are young adults. Victims may overestimate or underestimate

the age of some people in the group of

offenders. In some cases, they may perceive adults to be juveniles; in others,

they may perceive juveniles to be adults.

There is no reason, however, to believe

that these errors in identifying the age of

offenders will be in one direction. Indeed,

it seems more likely that these errors will

be in both directions and will therefore be

offsetting to some degree. This would

mean that any ambiguity in distinguishing

“juvenile offending” comes largely from

the prevalence of co-offending or group

offending (specifically group offending

that involves both juveniles and young

adults), not from victims’ misidentification of offenders’ age.

5. All comparisons of statistics made in

this report are statistically significant at

the 0.1 level or less. The standard errors

used in these statistical tests take into

account the complex sampling used in

the NCVS.

6. This pattern is broadly consistent with

the theories of Blumstein and Wallman

(2000) concerning the increase in violence

in cities during the late 1980s and early

1990s. They contend that the increases 

in violence were due initially to the drug

trade. Teenagers were recruited to participate in drug distribution, presumably

with adults. This would increase adult

co-offending. Participation in drug distribution required weapons, and the widespread carrying of weapons encouraged

even those not in the drug trade to arm

themselves. The availability of arms

among teenagers led to increases in serious violence among teenagers not involved in drug distribution. This could

explain increases in juvenile-only offending after the initial increases in adult

co-offending with juveniles.

7. The other serious violent crime category (forcible rape) is relatively rare (1.12

per 1,000), and trends are unstable.

8. The percentages for adult co-offending

were calculated from peaks in 1994.

9. As Blumstein and Wallman (2000) argue,

the routinization of the drug trade and the

decrease in violence attendant to the drug

trade may account for this. If juveniles

were recruited into the drug trade, it is

not unreasonable to assume that they participated in groups (even gangs) distributing drugs. In addition, it is reasonable to

assume that they would also participate

in the violence attendant to the drug

trade in groups. As the drug trade became more organized and less violent, the

need for group violence diminished. Even

if these juveniles did not participate in the

drug trade, living in areas with high levels

of violence virtually requires affiliation

with a group for protection. This, in turn,

increases the chance of co-offending.

References

Biderman, A.D., and Lynch, J.P. 1991. 

Understanding Crime Incidence Statistics:

Why the UCR Diverges From the NCS. New

York, NY: Springer Verlag.

Blumstein, A., and Wallman, J. 2000. The

Crime Drop in America. New York, NY:

Cambridge University.
18

Dodge, R. 1987. Series Crime: Report of a

Field Test. Technical Report. Washington,

DC: U.S. Department of Justice, Office 

of Justice Programs, Bureau of Justice 

Statistics.

Federal Bureau of Investigation. 1999.

Crime in the United States, 1998. Washington, DC: U.S. Department of Justice.

Jarvis, J.P., and Lynch, J.P. 1996. Towards

an error profile of the Uniform Crime

Reports: Assessing the effects of imputation. Unpublished paper presented at The

Workshop on the Quantitative Analysis of

Crime and Justice Data, Inter-university

Consortium for Political and Social Research, University of Michigan, August

2, 1996.

Kindermann, C., Lynch, J.P., and Cantor, D.

1997. The Effects of the Redesign on Victimization Estimates. Data Brief. Washington, DC: U.S. Department of Justice, Office

of Justice Programs, Bureau of Justice 

Statistics.

Lynch, J.P., Berbaum, M., and Planty, M.

1999. Investigating Repeat Victimization

With the National Crime Victimization 

Survey. Report to the National Institute 

of Justice.

Lynch, J.P., and Cantor, D. 1996. Models

for adjusting the NCS trend to account for

design differences between the NCS and

the NCVS. Memorandum to the American

Statistical Association Committee on Law

and Justice Statistics, May 28, 1996.

Maltz, M. 1999. Bridging the Gap in Police

Crime Data. Washington, DC: U.S. Department of Justice, Office of Justice Programs, Bureau of Justice Statistics.

Planty, M.G. 2000. Examining the differential returns from robbery incidents. Unpublished dissertation. Washington, DC:

American University, School of Public

Affairs.

Pope, C., and Snyder, H. In press. Race as

a Factor in Juvenile Arrests. Bulletin. Washington, DC: U.S. Department of Justice,

Office of Justice Programs, Office of Juvenile Justice and Delinquency Prevention.

Rand, M., Lynch, J.P., and Cantor, D. 1997.

Long Term Trends in Crime Victimization.

Washington, DC: U.S. Department of Justice, Office of Justice Programs, Bureau 

of Justice Statistics.

Rennison, C. 2000. Criminal Victimization

in the United States, 1999. Washington, DC:

U.S. Department of Justice, Office of Justice Programs, Bureau of Justice Statistics.

Singer, S. 1981. Homogeneous victimoffender populations: A review and some

research implications. Journal of Criminal

Law and Criminology 72(2):779–788.

Related Online OJJDP Publications

If you are interested in more information about juvenile violence and victimization, please consult the recently completed OJJDP publications listed below. These publications are

available in Adobe Acrobat and HTML online formats and

can be downloaded from OJJDP’s Web site (ojjdp.ncjrs.org).

Click on “Publications” to access an alphabetical list of titles

or to browse documents by topic area. You may also order

copies of these and other publications by calling the Juvenile Justice Clearinghouse at 800–638–8736.

Addressing Youth Victimization (NCJ 186667). This Action

Plan Bulletin explains that although violent crime has decreased significantly since publication of Combating Violence and Delinquency: The National Juvenile Justice Action

Plan in 1996, too many children continue to be victims of

violent crime, child abuse and neglect, and exposure to violence. In turn, this victimization perpetuates a cycle of violence in which children later become the perpetrators of

violence against others. This Bulletin describes a variety of

programs and services that have been implemented at the

State and local levels to address youth victimization and its

effects. Federal agencies are collaborating to support this

work through efforts such as the Coordinating Council’s call

to break the cycle of violence. Available at ojjdp.ncjrs.org/

pubs/violvict.html#186667.

Animal Abuse and Youth Violence (NCJ 188677). This

OJJDP Bulletin describes psychiatric, psychological, and

criminal research linking animal abuse to interpersonal violence perpetrated by juveniles and adults. Particular attention is focused on the prevalence of cruelty to animals by

children and adolescents and to the role of animal abuse

as a possible symptom of conduct disorder. In addition, the

motivations and etiology underlying the maltreatment of

animals are thoroughly reviewed. The Bulletin includes recommendations to curb such cruelty, while providing contact

information for additional resources concerned with violence

perpetrated against animals and people. Available at

ojjdp.ncjrs.org/pubs/violvict.html#188677.

Gun Use by Male Juveniles: Research and Prevention

(NCJ 188992). This OJJDP Bulletin examines patterns of gun

ownership and gun carrying among adolescents, drawing on

data from OJJDP’s Rochester Youth Development Study. The

Bulletin, which is part of the Youth Development Series, also

addresses the interrelationship between gangs and guns and

describes prevention programs, including the Boston Gun

Initiative, the Office of Community Oriented Policing Services’

Youth Firearms Violence Initiative, and OJJDP’s Partnerships

To Reduce Juvenile Gun Violence Program. Effective efforts

to reduce illegal gun carrying and gun violence among youth

require the support and participation of multiple community

agencies. The information presented in this Bulletin is intended to enhance those efforts. Available at ojjdp.ncjrs.org/

pubs/violvict.html#188992.

Juvenile Delinquency and Serious Injury Victimization

(NCJ 188676).This OJJDP Bulletin draws on data from two

OJJDP longitudinal studies on the causes and correlates

of juvenile delinquency—the Denver Youth Survey and the

Pittsburgh Youth Study—to explore the interrelationship between delinquency and victimization. The Bulletin, part of

OJJDP’s Youth Development Series, focuses on victims of

violence who sustained serious injuries as a result of the

victimization. Being victimized may lead to victimizing others.

The studies found that many victims were prone to engage

in illegal activities, associate with delinquent peers, victimize

other delinquents, and avoid legal recourse in resolving conflicts. A clearer understanding of the patterns and predictors

of victimization offers the potential for increased effectiveness

in designing and implementing strategies to reduce both victimization and offending. Available at ojjdp.ncjrs.org/pubs/

violvict.html#188676.
19

Acknowledgment

James P. Lynch is a Professor in 

the Department of Justice, Law, 

and Society at American University.

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it in your newsletter or journal. However, if you reprint, please cite OJJDP and the

authors of this Bulletin. We are also interested in your feedback, such as how you

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meet your individual or agency needs. Please direct your comments and questions

to:

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This paper was prepared with funds provided

to the National Center for Juvenile Justice 

by the Office of Juvenile Justice and Delinquency Prevention to support its National

Juvenile Justice Data Analysis Project

(1999–JN–FX–K002). 

Points of view or opinions expressed in this

document are those of the author and do not

necessarily represent the official position or

policies of OJJDP or the U.S. Department of

Justice.

The Office of Juvenile Justice and Delinquency

Prevention is a component of the Office of

Justice Programs, which also includes the

Bureau of Justice Assistance, the Bureau of

Justice Statistics, the National Institute of

Justice, and the Office for Victims of Crime.

Snyder, H. 2000. Juvenile Arrests 1999.

Washington, DC: U.S. Department of Justice, Office of Justice Programs, Office

of Juvenile Justice and Delinquency 

Prevention.

Snyder, H., and Sickmund, M. 1999. Juvenile Offenders and Victims: 1999 National

Report. Washington, DC: U.S. Department

of Justice, Office of Justice Programs, Office of Juvenile Justice and Delinquency

Prevention.

Thornberry, T., and Krohn, M. 2000. The

self-report method for measuring delinquency and crime. In Criminal Justice

2000: Measurement and Analysis of Crime

and Justice, vol. 4, edited by D. Duffee,

D. McDowall, B. Ostrom, R. Crutchfield,

S. Mastrofski, and L. Mazerolle. Washington, DC: U.S. Department of Justice, Office

of Justice Programs, National Institute of

Justice.

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