By

Janet L. Lauritsen, Ph.D.

Fellow, BJS and Professor, University of Missouri-St. Louis

Robin J. Schaum

University of Missouri-St. Louis

Introduction

For more than three decades, the Nation has had two

national indicators of crime: the Uniform Crime Reporting

(UCR) program and the National Crime Victimization

Survey (NCVS). The UCR program contains information

that is voluntarily provided by police departments and

forwarded to the FBI. The NCVS gathers information from a

nationally representative sample of persons age 12 or older

to produce estimates of crime that are independent 

of the recording practices of criminal justice systems. Data

from the two programs are routinely used together to

provide a more complete assessment of crime in the United

States.1

Annual estimates of the number of crimes derived from

NCVS data have often been higher than the annual counts

in the UCR. There are several reasons why this may occur.

Most importantly, the NCVS data include crimes that are

not reported to the police.2

 According to recent estimates,

approximately 51% of violent victimizations and 64% of

property victimizations are not reported to the police. In

addition, NCVS counts may be higher if police departments

do not record all of the incidents that come to their attention

or do not forward the reports to the national UCR program.

Indeed, increased knowledge about crimes not reported to

the police and assessments of the reliability of police data

were two important reasons for the development of the

crime survey in the early 1970’s.

For some types of crimes in the NCVS and the UCR, it is

possible to reconcile apparent discrepancies in annual

estimates by taking into account differences in the coverage of both data series and adjusting the NCVS counts to

include only those incidents said to have been reported to

the police. When such adjustments are made, levels and

trends in burglary, robbery, and motor vehicle theft appear

similar in the NCVS and UCR. On the other hand, UCR and

NCVS levels and trends in aggravated assault and rape

continue to exhibit discrepancies after these kinds of adjustments are made. Remaining differences in levels or trends

in aggravated assault and rape may reflect broader

changes concerning the public’s willingness to report crime

to the police, the ways in which police departments record

crime, the quality of victimization survey data, or other

factors. It is clear that the differences in the methodologies

of the UCR and NCVS programs must be considered when

assessing both levels and trends of crime in the Nation. 

When State and local governments are interested in

assessing levels or trends in crime in their own areas, they

typically rely solely on police data because victimization

survey data are rarely available for places other than the

Nation as a whole. The collection of reliable crime survey

data is costly and most State and local governments have

not had the resources to conduct their own victimization

surveys, especially on an annual basis. Knowing that crime

may not be reported to the police or fully recorded, many

wonder whether police-based estimates for local areas

provide an accurate foundation on which to assess levels or

short- or long-term trends in crime. In addition, many

wonder whether conclusions drawn from national police and

victim survey data also apply to their local areas.

To examine how police records compare to victimization

survey estimates for places other than the Nation as a

Crime and Victimization in the Three

Largest Metropolitan Areas, 1980-98 

March 2005, NCJ 208075

Bureau of Justice Statistics

Technical Report

U.S. Department of Justice

Office of Justice Programs

1

 In this report the terms “police data” and “UCR data” are used

interchangeably. For more detail about the UCR and NCVS

programs, see “The Nation’s Two Crime Measures,” Bureau of

Justice Statistics, 2003, NCJ 122705.

2

 For more details, see Hart and Rennison (2003), Reporting

Crime to the Police, 1992-2000, Bureau of Justice Statistics, 

NCJ 195710.
whole, the Bureau of Justice Statistics (BJS) and the U.S.

Census Bureau have developed special subsets of NCVS

data that are capable of providing survey-based estimates

of crime for the largest metropolitan areas in the country.

This report compares NCVS and police estimates of

burglary, robbery, and aggravated assault for the country’s

three largest metropolitan areas — New York, Chicago, and

Los Angeles — for 1980 through 1998. The features of the

NCVS sample limit the UCR-NCVS comparisons to the core

counties that comprise each of these metropolitan areas

(described below). These comparisons can be used to

inform the public about the levels and trends in criminal

victimization in these three areas. They also provide information about the correspondence between police and victim

survey data throughout the 1980’s and 1990’s for the New

York, Chicago, and Los Angeles areas.

Characteristics of the data

NCVS estimates

The NCVS, and its predecessor, the National Crime Survey

(NCS), are household-based surveys designed to gather

information about victimization directly from the public. A

random sample of U.S. households is generated using a

multistage stratified sampling procedure. The result is a

representative sample of households and persons ages 12

or older living in households.3

 The Census Bureau develops the sample and administers the survey for BJS.

The sampling strategy for the NCVS is developed explicitly

to provide national estimates of criminal victimization.

Generally speaking, the sample design is capable of providing local area estimates of crime only for certain places.

Heavily populated metropolitan areas constitute unique selfrepresenting portions of the sample; as a result, it is possible to use the data from the largest of those areas to form

reliable survey-based estimates of crime for those places.4 

 

Two important limitations of the NCVS metropolitan area

data should be noted. First, the boundaries of metropolitan

areas often change due to population shifts and development patterns. To ensure that metropolitan area victimization rates remain comparable over time, it is necessary to

restrict the geographic boundaries of the areas to the core

counties that remained continuously part of each metropolitan area from 1980 through 1998. For the New York core

county area, the sample includes residents from Bronx,

Kings, New York, Queens, Richmond, Putnam, Rockland,

and Westchester Counties.5

 For the Chicago core county

 2

3

Persons not living in households, such as homeless, 

institutionalized or incarcerated persons, are not included 

in the sample design.

1999 155,500 4,455 6,510 5,668 9.24

1998 157,800 4,566 6,773 5,799 9.23

1997 158,940 4,512 6,709 6,081 9.22

1996 170,660 4,253 6,413 5,981 9.24

1995 179,800 4,296 6,591 6,126 9.27

1994 181,120 4,424 6,510 6,200 9.32

1993 186,840 4,568 6,598 6,204 9.36

1992 152,000 5,089 7,025 6,501 9.39

1991 167,000 5,242 7,303 6,837 9.40

1990 190,000 5,351 7,237 6,778 9.43

1989 194,000 5,319 7,055 6,890 9.49

1988 202,000 5,244 6,951 6,943 9.53

1987 200,000 5,190 7,070 7,010 9.57

1986 200,000 5,189 7,182 7,187 9.58

1985 204,000 5,365 6,725 7,360 9.56

1984 228,000 6,138 7,805 8,116 9.57

1983 254,000 7,075 8,790 9,434 9.57

1982 254,000 7,136 8,590 9,285 9.55

1981 252,000 7,087 8,252 8,796 9.56

1980 246,000 6,901 8,230 9,072 9.60

1979 246,000 6,249 7,364 8,350 9.68%

Year Total for U.S. Chicago Los Angeles New York City represented by 3 cities

Number of NCVS interviews over 12-month period Percent of U.S. total 

Table 1. Interviews in the metropolitan areas of Chicago, Los Angeles, and New York as a percentage 

of all NCVS interviews, 1979-99.

4

The NCVS sample is generated in two stages. During the first

stage, primary sampling units (PSU's) are designated to reflect

metropolitan areas, counties, and groups of counties. Larger

PSU's (reflecting metropolitan areas) are termed selfrepresenting (SR) and are automatically included in the sample.

Smaller PSU's (non-self-representing or NSR PSU's) are

grouped together in similar strata based on known Census

geographic and demographic characteristics. From the NSR

PSU's, sample PSU's are selected by probability proportionate

to population size.

5

For an extensive analysis comparing UCR and NCVS rates for

New York City, see Langan and Durose, "The Remarkable Drop

in Crime in New York City," ISTAT (Italy's National Institute of

Statistics) meeting “per una societa pie secura,” Rome, December 3-5, 2004. 
area, residents are selected from the city and Cook,

DuPage, and McHenry Counties. For the Los Angeles core

county area, residents of the city and Los Angeles County

form the sample used in these victimization estimates. 

Second, compared to the national sample, the number of

persons interviewed within each metropolitan area in a year

is relatively small (table 1). Altogether these three metropolitan core county areas constitute roughly 9.5% of the

U.S. population. Sample size places statistical limitations on

the types of crimes that can be reliably estimated for each

metropolitan area and year. The three crimes that occur

with sufficient statistical regularity to permit comparisons

with police data are burglary, robbery, and aggravated

assault. To maximize the reliability of the NCVS metropolitan area estimates of burglary, robbery, and aggravated

assault victimization, 3-year moving averages are used for

NCVS crime rate estimates. 

Police estimates

Police counts of burglary, robbery, and aggravated assault

in each metropolitan area are based on offenses known to

the police departments with jurisdiction in each of the core

county areas.6

 Police data for each county and year were

gathered from different sources for each metropolitan area.

Population data for each county and year were obtained

from the Census Bureau so that standardized rates could

be used for comparisons. 

In each metropolitan area, police-based crime rates rely on

summaries from multiple police departments and jurisdictions. As a result, it is not possible to draw conclusions

about the reporting practices of any particular police department within the metropolitan area. Nonetheless, it is possible to illustrate the degree of correspondence between the

two data series by comparing the crime rates based on

police department records to those estimated by the survey.

Nature of the comparisons

Three sets of estimates are provided for each crime type,

year, and metropolitan area. The first set of estimates,

based on NCVS data, is designated “NCVS Crime Rates.”

They consist of the burglary, robbery, and aggravated

assault victimization rates regardless of whether the

incident was reported to the police.7

 The second set of

estimates, also based on NCVS data, is the victimization

rates based on incidents that victims said were reported to

the police. These estimates are referred to as “NCVS

Reported Crime Rates.” The third set of estimates, based

on police records, consists of the UCR crime rates for each

metropolitan area. These estimates are referred to as “UCR

Crime Rates.” 

For each metropolitan area and crime type, the NCVS

Crime Rates are compared with the NCVS Reported Crime

Rates to assess whether levels of reporting crime to the

police have changed appreciably.8

 The NCVS Reported

Crime Rates are compared to the UCR Crime Rates

3

6

Because police departments voluntarily submit data to the UCR

a large amount of data is missing across time and places. This

missing data issue made it difficult to collect consistent data

across all of the counties over the 20-year period. For this

reason, the police data used here for the metropolitan core

county areas of New York and Chicago were gathered from their

respective State criminal justice websites rather than from the

UCR reports. The New York metropolitan area police data were

retrieved from the New York State Division of Criminal Justice

Services at <http://www.criminaljustice.state.ny.us/>. The

Chicago metropolitan area police data were retrieved from the

Illinois Criminal Justice Information Authority at <http://www.

icjia.state.il.us/public/>. The Chicago core county police data

were not complete for 1979 through 1982. Unlike police data for

the Chicago and New York areas, the Los Angeles metropolitan

area data were complete. Therefore, the Los Angeles area data

were obtained directly from UCR records.

7

Because the NCVS is a household-based survey, it includes

residential burglaries but not commercial burglaries. The UCR

data that were available to us included both residential and

commercial burglaries. Because we were unable to determine

how many of the police recorded burglaries were against

commercial establishments in each county and year, the UCR

burglary rates are expected to be higher than the NCVS reported

burglary rates. Also, unlike the NCVS burglary rate which is

typically based on the number of households, the UCR burglary

rate is measured by taking the total number of burglaries known

to the police and dividing by the total number of persons. To

make the NCVS and UCR burglary rates as comparable as possible, the NCVS rates were estimated using persons age 12 or

over in the denominator. In addition, it was not possible to determine how many of the police recorded robberies and aggravated

assaults were against persons under age 12 (incidents excluded

from the NCVS because persons under age 12 are not interviewed). As a result, the NCVS robbery and aggravated assault

rates were created by dividing the number of victimizations by the

population age 12 or over, while the UCR rates were created by

dividing the total number of offenses known divided by the total

population for each county and year. UCR rates based on the

total population age 12 or over in the denominator also were

calculated to check the sensitivity of the findings to differences in

population coverage. Of course, the UCR rates increased when

the denominator was restricted to the population age 12 or over.

However, the substantive conclusions reported here were similar

regardless of which denominator was used for the UCR and

NCVS rates. 

8

Significant changes were made to the methodology of the NCVS

in 1992. To make the NCVS rates comparable before and after

1992, the earlier rates were weighted by their crime specific

adjustment factors. These weights were derived from assessments of how national estimates changed following a phase-in of

the new methodology. There is little reason to suspect that the

effects of the new methodology varied across these three metropolitan areas. For more information on the weighting of crimes,

see Kindermann, C., Lynch, J., and Cantor, D. (1997), Effects of

the Redesign on Victimization Estimates, Bureau of Justice

Statistics, NCJ 164381.
to ascertain the correspondence between police data and

victim reports for each metropolitan area. 

Burglary

New York Metropolitan Area

For the core counties of the New York metropolitan area,

both police and survey data agree that burglary declined

from 1980 to 1998 (figure 1). And as expected, the total

NCVS burglary rate was higher than the UCR burglary rate.

According to New York area victims, roughly 61% of burglaries were reported to the police over these two decades.

The gap between the NCVS burglary rates and the NCVS

reported burglary rates appears to have diminished

somewhat in the New York metropolitan area, suggesting

an increase in reporting to the police.9

 

Throughout the 1980’s and 1990’s, the NCVS reported

burglary rate was similar to the UCR burglary rate. The

correspondence in these two trends indicates that the UCR

burglary data for the New York metropolitan area closely

match both the levels and trends indicated by the victim

survey data.

Chicago Metropolitan Area

Police and survey estimates for burglary in the Chicago

metropolitan area agree that there was a decline in burglary

throughout the 1980’s and 1990’s (figure 2). The NCVS

burglary rate was higher than the UCR rate, with victims in

the Chicago area stating that 52% of burglaries were

reported to the police over this period. The gap between the

NCVS burglary rates and the NCVS reported burglary rates

was somewhat reduced later in the series, suggesting that

there may have been an increase in reporting to the police

over these two decades.

 4

1980 1983 1986 1989 1992 1995 1998

0

10

20

30

40

50

60

Number per 1,000 population

*3-year moving average

NCVS burglary victimizations*

UCR burglaries

NCVS burglaries reported*

Figure 1. Burglary rates for New York City Metropolitan

Area, 1980-98

1980 1983 1986 1989 1992 1995 1998

0

10

20

30

40

50

60

70

Number per 1,000 population

*3-year moving average

NCVS burglary victimizations*

UCR burglaries

NCVS burglaries reported*

Figure 3. Burglary rates for Los Angeles Metropolitan 

Area, 1980-98

1980 1983 1986 1989 1992 1995 1998

0

10

20

30

40

50

60

Number per 1,000 population

*3-year moving average

NCVS burglary victimizations*

UCR burglaries

NCVS burglaries reported*

Figure 2. Burglary rates for Chicago Metropolitan Area,

1980-98

9

The statistical limitations associated with the size of the 

metropolitan area sample do not permit one to conclude that this

change is statistically significant. Statements about differences

between the UCR crime rates and the NCVS crime reported to

police rates are based on the point estimates shown in the

figures and not strictly on significance testing. The reason for

this is that even though 3-year moving averages are used for the

NCVS rates, the 95% confidence intervals around those

averages are, at a minimum, plus or minus 4 per 1,000. Thus,

very few of the annual differences between a UCR rate and an

NCVS reported to police rate would be statistically significant.

The purpose of these analyses is not to determine the specific

years in which the two rates are or are not statistically significant

for each crime type and metropolitan core county area, but to

show the broader patterns of correspondence between police

data and victim survey reports.
In the Chicago metropolitan area, the NCVS reported

burglary rate is somewhat higher than the UCR burglary

rate during the early years of the time series. In later years,

the NCVS reported burglary rate and the UCR burglary rate

corresponded more closely. Although long-term trends in

the victim and police data indicate a general decline in

burglaries reported to police, the decline appears greater in

in the NCVS data than in the Chicago metropolitan area

police data.

Los Angeles Metropolitan Area

In the Los Angeles metropolitan region, police and survey

data agree that the burglary rate declined throughout much

of the 1980’s and 1990’s (figure 3). The exception to the

decline appeared in the late 1980’s when the NCVS rates

suggested an increase in residential burglary victimization.

The decline in burglary in the Los Angeles region appeared

larger than the declines in the New York and Chicago areas

because the survey based rates in Los Angeles were higher

in the earlier years of the time series. According to victims,

the level of reporting burglary to the police averaged 50%

over the two decades, with no apparent change in the level

at which residential burglary was reported to the police.

Throughout much of the 1980’s and 1990’s, the NCVS

reported burglary rate was similar to the UCR burglary rate

in the Los Angeles metropolitan area. Since the early

1990’s, the two data series have shown similar short and

long-term trends in burglary victimization.

Robbery 

Unlike residential burglary, robbery can take place away

from home. This fact makes comparisons of UCR and

NCVS robbery data more complex. If a nonresident, such

as a tourist or commuter, is victimized by robbery while in

the metropolitan area, the crime (if reported) is likely to be

reported to the police department with jurisdiction in the

area where the incident occurred. This means that UCR

robbery counts for metropolitan areas include crimes

committed against nonresidents. NCVS robbery counts, on

the other hand, are based only on interviews with persons

who reside in the metropolitan core county areas. If UCR

robbery rates for the New York, Chicago, and Los Angeles

areas contain many incidents against persons who live

outside these counties, they will be higher than the local

NCVS robbery rates.10 

5

1980 1983 1986 1989 1992 1995 1998

0

10

20

30

Number per 1,000 population

*3-year moving average

NCVS robbery victimizations*

UCR

NCVS robberies reported*

robberies

Figure 5. Robbery rates for Chicago Metropolitan Area,

1980-98

10UCR robbery rates also will be higher than NCVS robbery rates

if police robbery data include many incidents against persons who

are not part of households (for example, homeless persons).

Such persons are ineligible to participate in household-based

surveys.

1980 1983 1986 1989 1992 1995 1998

0

10

20

30

Number per 1,000 population

*3-year moving average

NCVS robbery victimizations*

UCR

NCVS robberies reported*

robberies

Figure 4. Robbery rates for New York City Metropolitan

Area, 1980-98

1980 1983 1986 1989 1992 1995 1998

0

10

20

30

Number per 1,000 population

*3-year moving average

NCVS robbery victimizations*

UCR

NCVS robberies reported*

robberies

Figure 6. Robbery rates for Los Angeles Metropolitan 

Area, 1980-98
Alternatively, if many of the robberies against metropolitan

area residents took place while they were outside of the

core counties of their metropolitan areas, the NCVS

estimates could be higher than UCR estimates. The NCVS

counts do not easily distinguish victimizations that occurred

inside the metropolitan core county area from those that

occurred outside. Little evidence indicates which of the

above concerns is more problematic. To resolve the issue

would require additional information about the residence of

each victim in UCR records and location information for

each incident in the NCVS reports. The UCR-NCVS correspondence in robbery will reflect in part, the extent to which

these two concerns are relatively equal.

New York Metropolitan Area

Police and victim survey data for the New York metropolitan

area agree that robbery rates have generally declined over

the past two decades (figure 4). As expected, NCVS

robbery rates were higher than UCR rates, but both exhibit

similar long-term trends. On average, about 53% of robberies that occurred to residents were reported to the police,

with no statistically significant changes in reporting between

the early and later portions of the time series. Nonetheless,

the NCVS data suggest a decrease in the reporting of

robbery to the police in the New York metropolitan area

from approximately 1989 to 1994.

From the mid-1980’s until the mid-1990’s, annual UCR

robbery rates were higher than NCVS reported robbery

rates. Given the limitations associated with the size of the

sample, the annual differences were not large enough to be

statistically significant. Even so, this difference in robbery

rates may be important. If one assumes that the reliability of

the UCR and NCVS robbery rates did not change during

this time period, the higher UCR rates may have reflected a

relatively higher occurrence of robberies against nonresidents of the New York metropolitan area during these years.

The higher UCR rate might also indicate a relatively greater

increase in robbery against persons not captured in the

NCVS sample, such as homeless persons. If crimes against

such groups increased at rates higher than it did among

others, UCR robbery rates could be higher than NCVS

reported robbery rates.

Chicago Metropolitan Area

Both police and victim survey data for the Chicago metropolitan area suggest that robbery rates were lower in the

late 1990’s compared to the early 1980’s (figure 5). Both

data series show that the declines in the Chicago area were

relatively smaller than in the New York area during this

same time period. Over these two decades, the average

level of robbery reporting among residents was 56%, and

there appears to have been relatively little change in

reporting.

As in the New York metropolitan area, Chicago area UCR

robbery rates were somewhat higher than NCVS reported

robbery rates in several years. These differences were not

large enough to be found statistically significant. After 1984

the short and long-term trends in NCVS reported robbery

rates and UCR robbery rates generally corresponded,

although the police data on robbery peaked and began to

decrease about 2 years earlier than the survey data.

Los Angeles Metropolitan Area

In the Los Angeles metropolitan area, robbery rates based

on police and victim survey data were lower in the late

1990’s compared to the early 1980’s (figure 6). UCR and

NCVS data agree that Los Angeles area robbery rates

declined from the mid- to late-1990’s. The gap between

NCVS robbery rates and NCVS reported robbery rates

changed little in the Los Angeles area during the 1980’s and

1990’s. Roughly 49% of all robberies against residents were

reported to the police during these two decades.

Annual UCR robbery rates and NCVS reported robbery

rates were very similar throughout most of the 1980’s and

the latter half of the 1990’s. As was found in the New York

and Chicago metropolitan areas, the Los Angeles area UCR

robbery rates were somewhat higher than NCVS reported

robbery rates in selected years of the series (roughly 1989

through 1993). Similarly, these annual differences were not

large enough to be statistically significant. As noted earlier,

the higher UCR robbery rate may reflect more robberies

against nonresidents or against persons not captured by the

survey during this time period. 

Aggravated assault

Like robbery, comparisons of police and victim survey data

for aggravated assault involve unique complexities. Police

data will include an unknown number of crimes committed

against nonresidents, and residents may become victims of

aggravated assault when they are outside of their metropolitan area. Police data will also include an unknown number

of crimes against persons ineligible or unlikely to participate

in the NCVS. But the measurement of aggravated assault

also is unique in that it is likely to have been affected by

broad scale changes in police response to domestic assault

incidents. Mandatory arrest policies have replaced informal

dispositions in many areas of the Nation. As a result, trends

exhibited in police data may not correspond closely with

trends based on survey data, but instead reflect changes in

police handling of aggravated assault incidents. 

New York Metropolitan Area

In the New York area, the NCVS data indicate that there

were fluctuations in aggravated assault levels, followed by a

gradual decrease in the later 1990’s (figure 7). Comparisons

of NCVS aggravated assault rates and the NCVS reported

 6
aggravated assault rates show no significant changes in the

level at which these crimes were reported to the police. 

About 56% of all aggravated assaults against New York

area residents were reported to the police. Police data for

aggravated assault suggest that there was a gradual

increase in this crime throughout the 1980’s, followed by a

gradual decline in the 1990’s. Compared to burglary and

robbery, the correspondence between police and survey

estimates of aggravated assault levels and trends was

lower. During much of the 1980’s and 1990’s the police rate

of aggravated assault was higher than the NCVS reported

rate. In several years the police-based rate of aggravated

assault in the New York metropolitan area was greater than

the total NCVS rate. Although the two series suggest different trends during some years, there was greater similarity in

the trends in the latter half of the 1990’s. 

Chicago Metropolitan Area

NCVS rates of aggravated assault in the Chicago metropolitan area show a mixed set of trends. The survey data

suggest that rates were at their highest in the early 1980’s

and lowest in the later 1990’s (figure 8). The gap between

the NCVS aggravated assault rate and the NCVS reported

aggravated assault rate remained relatively consistent

throughout the two decades. Fifty-one percent of residents’

aggravated assaults were reported to the police during

these years.

The correspondence between the police and survey

estimates of aggravated assault was lower in the Chicago

area than the correspondence for the crimes of burglary

and robbery. Police rates of aggravated assault suggest

increases until the early 1990’s, while NCVS rates suggest

that the rates were highest in the early 1980’s. More fluctuations also were exhibited in the survey estimates than in the

UCR data. The lower degree of correspondence between

the NCVS aggravated assault rates and the UCR rates

makes it difficult to draw conclusions about more recent

short-term trends in aggravated assault. 

Los Angeles Metropolitan Area

In the Los Angeles area, the NCVS data exhibit no clear

long-term trend in the risk for aggravated assault victimization (figure 9). The UCR rates, on the other hand, suggest

stability in the early 1980’s, an increase in the later 1980’s,

and a steady decrease beginning around 1992. The gap

between the NCVS aggravated assault rate and the rate

reported to police was steady, and the average level of

reporting among residents was approximately 50%. 

7

1980 1983 1986 1989 1992 1995 1998

0

5

10

15

20

Number per 1,000 population

*3-year moving average

NCVS aggravated assaults reported*

aggravated assaults

NCVS aggravated assault victimizations*

UCR

Figure 7. Aggravated assault rates for New York City 

Metropolitan Area, 1980-98

1980 1983 1986 1989 1992 1995 1998

0

5

10

15

20

Number per 1,000 population

*3-year moving average

NCVS aggravated assaults

aggravated assaults

NCVS aggravated

UCR

assault victimizations*

reported*

Figure 8. Aggravated assault rates for Chicago 

Metropolitan Area, 1980-98

1980 1983 1986 1989 1992 1995 1998

0

5

10

15

20

Number per 1,000 population

*3-year moving average

NCVS aggravated assaults reported*

aggravated assaults

NCVS aggravated assault

UCR

victimizations*

Figure 9. Aggravated assault rates for Los Angeles

Metropolitan Area, 1980-98
Both police and victim survey data in the Los Angeles

metropolitan area agree that aggravated assault began to 

decrease gradually in the early 1990’s. But for earlier years,

the two series often suggested different year-to-year

changes in aggravated assault rates. Nonetheless, the UCR

rates were similar to the NCVS reported rates, indicating

agreement about the level of aggravated assault brought to

the attention of the police. 

Conclusions

As noted earlier, local governments often are interested in

assessing levels or trends in crime, but they typically draw

conclusions about crime in their areas solely on the basis 

of police data. These analyses have examined how police

data compare to victim survey data for burglary, robbery,

and aggravated assault for the three largest metropolitan

areas in the Nation. For burglary and robbery, UCR crime

rates were generally similar to NCVS reported crime rates in

the New York, Chicago, and Los Angeles areas for 1980

through 1998. Police and victim survey data were more

likely to show discrepancies in levels and trends of aggravated assault, a crime that is likely to have been affected by

broader policy changes in police handling of domestic

violence incidents.

Even though UCR rates and NCVS reported rates often

suggest different levels and trends in aggravated assault,

there are many instances in which the two data series

provide statistically similar annual estimates for this crime.

For the Los Angeles metropolitan area for example, annual

differences between the UCR rates and NCVS reported

rates rarely were statistically significant. And for the New

York and Chicago areas, the UCR rates and NCVS reported

rates did not differ significantly in many of the years. Statistical significance is a function of both sample size and the

magnitude of the difference between the NCVS reported

rate and the UCR rate. Given the relative rarity of aggravated assault and the sample size limitations noted earlier, it

is not surprising that few statistically significant differences

are found. Nonetheless, the differences between some of

the UCR and NCVS annual estimates of aggravated assault

provide important information about the sensitivity of these

estimates to methodological differences between the two

sources of data.

 8

Office of Justice Programs

Partnerships for Safer Communities

http://www.ojp.usdoj.gov

U.S. Department of Justice

Office of Justice Programs

Bureau of Justice Statistics

Lawrence A. Greenfeld

Director

Janet L. Lauritsen, Professor, University of Missouri-St.

Louis, and Robin J. Schaum, University of Missouri-St.

Louis, wrote this report. The U.S. Census Bureau, in

cooperation with BJS, produced the data for the analyses

presented. Lawrence Greenfeld, Marshall DeBerry, Matt

Durose, Patrick Langan, and Michael Rand at BJS and

Marilyn Monahan at the Census Bureau assisted. 

Professor Lauritsen was a Visiting Fellow at BJS and

produced this report under cooperative agreement 2002-

BJ-CX-0002. Findings and conclusions reported here are

those of the authors and do not necessarily reflect the

official position or policies of the U.S. Department of

Justice and the Bureau of Justice Statistics.

Address all correspondence to Professor Lauritsen at

Department of Criminology and Criminal Justice, University of Missouri-St. Louis, 1 University Blvd., St. Louis, MO

 63121, or Janet_Lauritsen@umsl.edu.

March 2005, NCJ 208075