By Ramona R. Rantala

BJS Statistician

with technical support from

Thomas J. Edwards

FBI Systems Analyst

In 1929 the FBI began the Summary

Uniform Crime Reporting (UCR)

system, a voluntary program to collect

aggregate counts of Index crimes &

murder, rape, robbery, aggravated

assault, burglary, motor vehicle theft,

larceny, and, after 1978, arson.

“ . . . [T]he Summary system of the

UCR Program has been very serviceable since its inception in 1929,” the

FBI notes, “but it pales next to the

capabilities and potential of the

National Incident-Based Reporting

System (NIBRS).”1

“In developing NIBRS, UCR Program

managers have provided law enforcement agencies with a standardized,

electronic blueprint for storing the

NIBRS data within their individual

records management systems.... The

goals of NIBRS are to enhance the

quantity, quality, and timeliness of

crime data collection ... and to improve

the methodology used in compiling,

analyzing, auditing, and publishing the

collected crime statistics.”2

As jurisdictions switch from the

Summary UCR system to NIBRS,

many have expressed concern about

Differences between 

Summary UCR and NIBRS

Summary UCR

 ̆ Consists of monthly aggregate

crime counts for eight Index crimes

 ̆ Records one offense per incident as

determined by hierarchy rule

 ̆ Hierarchy rule suppresses counts 

of lesser offenses in multiple-offense

incidents

 ̆ Does not distinguish between

attempted and completed crimes

 ̆ Applies hotel rule to burglary

 ̆ Records rape of females only

 ̆ Collects weapon information for

murder, robbery, and aggravated

assault

 ̆ Provides counts on arrests for the 8

Index crimes and 21 other offenses.

NIBRS

 ̆ Consists of individual incident

records for the 8 Index crimes and 38

other offenses with details on &

y Offense  ̆ Victim

y Offender  ̆ Property

 ̆ Records each offense occurring 

in incident

 ̆ Distinguishes between attempted

and completed crimes

 ̆ Expands burglary hotel rule to

include rental storage facilities

 ̆ Records rape of males and females

 ̆ Restructures definition 

of assault

 ̆ Collects weapon information for 

all violent offenses

 ̆ Provides details on arrests for the 8 

Index crimes and 49 other offenses.

Sources of data discrepancies

between Summary UCR and NIBRS

Human error

Misclassifications of &

y Aggravated assault

y Motor vehicle theft

y Larceny

Hierarchy

y Suppression of multiple

offenses by hierarchy rule

Operational

y Modified offense definitions

y Converting State penal code 

to FBI crime definitions

y Over-reporting because of 

State practices

y Recording every possible

offense with which offender

may be charged

Computer

y Inadequate programming

 

When comparing data from the same

year for the jurisdictions in this study,

NIBRS rates differ only slightly from

Summary UCR &

 ̆ Murder rates are the same

 ̆ Rape, robbery, and aggravated

assault rates in NIBRS are about 1%

higher, on average, than in Summary

UCR

 ̆ NIBRS burglary rates are lower by

an average 0.5%

 ̆ NIBRS larceny rates are higher by

an average 3.4%

 ̆ NIBRS motor vehicle theft rates are

higher by an average 4.5%.

Highlights

U.S. Department of Justice

Office of Justice Programs

Bureau of Justice Statistics

Special Report

 July 2000, NCJ 178890

Effects of NIBRS 

on Crime Statistics

1

FBI, CJIS Newsletter, NIBRS edition, 4, 1, p 1. 2

CJIS Newsletter, p. 2.
the effects incident-based reporting will

have on crime statistics. Under

Summary UCR agencies report only

the most serious Index offense per

incident of crime. Because of the new

type of crime classification procedures

in NIBRS, in a multiple-offense incident

more than one offense will be reported.

Jurisdictions are concerned about the

effect this more thorough reporting will

have on their crime statistics. 

Comparing crime rates from

Summary UCR and NIBRS

Research for this report measured

differences between estimates of the

aggravated assault rate, comparing

NIBRS to summary format, and identified possible causes of those differences. Differences in the rates for six

other Index crime categories are

examined to compare with aggravated

assault. Arson, which the FBI reports

in the “Modified Index” but not the

Index crime figures, is not included.

The Bureau of Justice Statistics (BJS)

selected jurisdictions with full-year

NIBRS reporting and nonzero

populations (that is, including agencies

with a specific population, such as a

local police department or sheriff’s

office, and generally excluding State or

county police). In 1991, 269 agencies,

covering a population of 4.1 million,

met the criteria. By 1996, full-year

NIBRS participation had increased to

1,082 agencies, covering a population

of 14.8 million (figure 1). The data

came from nine NIBRS- certified

States (Idaho, Iowa, Massachusetts,

Michigan, North Dakota, South

Carolina, Utah, Vermont, and Virginia).

Each agency is represented for each

year in which it met the selection

criteria. Although 156 agencies had a

single year of data, the rest of the

agencies met the criteria for more than

1 year (table 1). The term “case” in

this report refers to an “agency-year.”

A case includes both NIBRS and

Summary UCR aggregate crime

counts within each agency for each

year an agency reported 12 months of

NIBRS data. A total of 4,068 cases,

comprising 1,131 unique agencies, met

these selection criteria.

Two FBI datasets were used. In the

first dataset, the FBI provided NIBRS

offense counts aggregated by agency

from 1991 to 1996. Ten crime

categories, as defined in the Summary

UCR program, were included (figure 2).

Through a computer program the FBI

applied the hierarchy rule and converted the NIBRS counts to Summary

UCR counts. This process resulted in

two crime counts, NIBRS and

Summary UCR, for each crime

category, agency, and year.

2 Effects of NIBRS on Crime Statistics 

Figure 1

Property offenses

Violent offenses

Index crimes

Larceny

Motor vehicle theft

Burglary

Aggravated assault

Robbery

Rape

Murder

-1% 0% 1% 2% 3% 4% 5%

Offenses in jurisdictions of all sizes

Average percent difference in crime rates when reported through

NIBRS rather than Summary UCR

The rates of violent crime from

NIBRS were on average less than 

1% higher than rates from data

defined by Summary UCR

Figure 2

1991 1992 1993 1994 1995 1996

0

200

400

600

800

1,000

1,200

Number of agencies reporting NIBRS

1991 1992 1993 1994 1995 1996

0

5

10

15

Population (in millions) covered

by agencies reporting NIBRS

Among law enforcement agencies that reported 12 months of NIBRS data and that were the primary 

policing agencies for residents, the number grew from 269 agencies serving 4.1 million persons in 1991

to 1,082 agencies serving 14.8 million in 1996

6 250 1,500

5 247 1,235

4 80 320

3 61 183

2 337 674

1 156 156

Total 1,131 4,068

Years Agencies Cases

Table 1. Agencies with 12 months

of NIBRS reporting and nonzero

population, by the number of years 

of reporting, 1991-96
The second data set was the 1996

NIBRS incident file. This file provided

detail at the incident level, such as

which crimes occurred in combination

for multiple offense incidents and the

number of victims and offenders.

These details help explain some of the

crime rate differences. 

Overall results

When the crime rates were calculated

from NIBRS and Summary UCR data,

the average difference between

estimates was small. On average the

NIBRS Index crime rate was 2% higher

(figure 2). The violent crime rate was

higher by less than 1%, and the

property crime rate was higher by 

slightly more than 2%, on average.

For murder, rates from NIBRS and

Summary UCR are the same because

both systems count each homicide and

manslaughter victim and exclude

justifiable homicide.

Rape, robbery, and aggravated assault

rates each had an average difference

of less than 1% between NIBRS and

Summary UCR statistics. 

NIBRS burglary rates were lower an

average of 0.5%. Burglary is the only

individual crime category in which the

NIBRS rate can be lower than

Summary UCR. (See page 5.)

Larceny rates were higher by slightly

more than 3% and motor vehicle theft

rates by 4.5%, on average.

Individually, most cases studied

showed only slight differences between

NIBRS and Summary UCR estimates.

For murder, 100% of the cases had

identical murder rates from the two

counting methods. 

In 3,970 cases of aggravated assault,

98% of all cases, the difference

between the rates from NIBRS and

Summary UCR was 5.5% or less.

Results for rape, robbery and total

violent crime were similar, with 97% of

cases showing differences of 5.5% or

less 

The results for property crime varied.

The proportion of cases having a rate

change of 5.5% or less was 97% for

burglary, 80% for motor vehicle theft,

and 88% for larceny. Overall, 90% of

cases showed rate changes of 5.5% or

less for both total property and total

index crime. 

Jurisdictions with little crime tend to

show exaggerated changes in crime

rates. For example, a jurisdiction that

experienced in a year two robberies,

one of which was in conjunction with a

murder, would count one robbery

under Summary UCR and two under

NIBRS. Though the actual count

differed by one, the percent difference

was 100%. Such jurisdictions should

rely on the actual numbers rather than

percent differences to express

changes in measurement or over time.

 Effects of NIBRS on Crime Statistics 3

*Cases are “agency-years” & agencies 

that submitted 12 months of NIBRS data 

for a year. 

Larceny 3,569 88

Motor vehicle theft 3,234 80

Burglary 3,953 97

Property offenses 3,643 90

Assault 3,970 98

Robbery 3,954 97

Rape 3,957 97

Murder 4,068 100

Violent offenses 3,937 97

All Index offenses 3,661 90%

Percent of

all cases

Number

of cases*

NIBRS crime rates differ

from Summary UCR 

by 5.5% or less 

All other offenses

Trespassing

Runaways

All other offenses (except traffic) Peeping Tom

Weapons: carrying, possessing, other Nonviolent family offenses

Vandalism Drunkenness 

Vagrancy Driving under the influence

Suspicion Disorderly conduct

Stolen property: buying, receiving, possessing Curfew/loitering/vagrancy

Sex offenses (except forcible rape and prostitution) Bad checks 

Runaways

Prostitution and commercial vice Group B offenses

Other assaults Arrests only are reported for the following:

Offenses against family and children 

Liquor laws Weapon law violations

Gambling Stolen property offenses

Fraud Sex offenses, nonforcible

Forgery and counterfeiting Sex offenses, forcible

Embezzlement Robbery

Drunkenness Prostitution offenses

Drug abuse violations Pornography/obscene material

Driving under the influence Motor vehicle theft

Disorderly conduct Larceny/theft offenses

Curfew and loitering law violations Kidnaping/abduction

Homicide offenses

Part II offenses Gambling offenses

Arrests only are reported for the following: Fraud offenses

Extortion/blackmail

Arson (not subject to the hierarchy rule) Embezzlement

Larceny Drug/narcotic offenses

Motor vehicle theft Destruction/damage/vandalism of property

Burglary & breaking or entering Counterfeiting/forgery

Aggravated assault Burglary/breaking and entering

Robbery Bribery

Forcible rape Assault offenses

Murder Arson

Part I (Index) offenses Group A offenses 

Offenses and arrests are reported for the

following, for which a hierarchy does not

apply:

Offenses and arrests are reported 

for the following, listed in hierarchical 

order:

Summary UCR NIBRS

Table 2. Offense categories for Summary UCR and NIBRS 
Differences in data collection and

crime classification between NIBRS

and Summary UCR

Data collection

In Summary UCR, for each of the

seven Index crime classifications

monthly totals are reported on five

elements: offenses reported or known

to police (including “unfounded”

offenses and attempts); unfounded,

that is, false or baseless complaints;

number of actual offenses (including

attempts); total offenses cleared by

arrest or exceptional means; and 

number of clearances involving only

persons under age 18. 

UCR collects weapon information for

murder, robbery, and aggravated

assault. Attempts are distinguished

from completed crimes only for forcible

rape. Murder attempts are reported as

aggravated assault for both Summary

UCR and NIBRS. Both systems also

count each victim of violent offenses.

For example, if an offender with a

weapon simultaneously injures two

victims in an assault, both systems

would record two aggravated assaults.

In incidents with multiple offenses,

Summary UCR records only the most

serious offense, as determined by the

hierarchy rule (table 2). Reported

separately, arson is not subject to the

hierarchy rule and is not included in

this study.

Collected information on stolen

property provides the number of

offenses and the monetary value of

property stolen for each Index crime.

These totals are recorded by where a

robbery took place; whether a burglary

occurred at a residence or nonresidence, night or day; nature of

larcenies; recovery of motor vehicles.

Summary UCR collects monetary value

of stolen and recovered property by

type of property on a supplemental

form.

Arrest data are collected for 21 Part II

offenses as well as the 8 Index crimes.

Instead of collecting aggregate counts

by offense category, NIBRS collects

detailed information by crime incident,

including offense, victim, offender,

property and arrest information (table

3). Each incident is assigned a

number for identifying all information

that pertains to it.

Details are collected for each occurrence within 8 Index and 38 other

specific Group A offenses in NIBRS.

(For a list of specific Part I, Part II,

Group A, and Group B offenses, see

appendix table 1.) These details

include information on weapons,

location, time of day, alcohol or drug

use by offender and hate/bias motivation. Attempts are distinguished from

completed crimes for all offenses. In

incidents with multiple offenses, all

offenses are reported.

Data collected on each victim, offender, and arrestee include age, sex, and

race. Relationship of victim to offender

is noted. NIBRS also collects detailed

information on type, value, description

and recovery of property; type and

quantity of drugs; and number of stolen

and recovered motor vehicles.

Arrest data are collected for 

11 Group B offenses in addition to 

the 22 Group A offense categories.

Crime classification

Summary UCR and NIBRS differ in

how they classify or define several

types of crimes. (See appendix 

table 2.)

Justifiable homicide is first recorded as

murder in Summary UCR, then as

unfounded. NIBRS records justifiable

homicide separately, not including it

with murder and manslaughter.

Neither includes justifiable homicide in

total counts, so that homicide statistics

are not affected. 

Other differences affect numbers of

specific offenses. NIBRS includes

male victims of female offenders in 

forcible rape, which would account 

for part of the higher rate that was

observed.

4 Effects of NIBRS on Crime Statistics 

Administrative segment:

1 ORI number

2 Incident number

3 Incident date/hour

4 Exceptional clearance indicator

5 Exceptional clearance date

Offense segment:

6 UCR offense code

7 Attempted/completed code

8 Alcohol/drug use by offender

9 Type of location

10 Number of premises entered

11 Method of entry

12 Type of criminal activity

13 Type of weapon/force used

14 Bias crime code

Property segment:

15 Type of property loss

16 Property description

17 Property value

18 Recovery date

19 Number of stolen motor vehicles

20 Number of recovered motor vehicles

21 Suspected drug type

22 Estimated drug quantity

23 Drug measurement unit

Victim segment:

24 Victim number

25 Victim UCR offense code

26 Type of victim

27 Age of victim

28 Sex of victim

29 Race of victim

30 Ethnicity of victim

31 Resident status of victim

32 Homicide/assault circumstances

33 Justifiable homicide circumstances

34 Type of injury

35 Related offender number

36 Relationship of victim to offender

Offender segment:

37 Offender number

38 Age of offender

39 Sex of offender

40 Race of offender

Arrestee segment:

41 Arrestee number

42 Transaction number

43 Arrest date

44 Type of arrest

45 Multiple clearance indicator

46 UCR arrest offense code

47 Arrestee armed indicator

48 Age of arrestee

49 Sex of arrestee

50 Race of arrestee

51 Ethnicity of arrestee

52 Resident status of arrestee

53 Disposition of arrestee under 18

Table 3. Information that NIBRS records on each crime incident
Because assault is integral to all violent

offenses, it is unaffected by the hierarchy rule in single-victim incidents.

Moreover, the definition of aggravated

assault is essentially the same for both

reporting systems. The difference in

treatment of aggravated assault by the

two systems lies in classification and

recording. Summary UCR collects

assaults in five categories: firearm;

knife or cutting instrument; other

dangerous weapon; hands, fists, feet,

and so on; and other & simple, not

aggravated. Though presence of a

weapon indicates aggravated assault,

if an incident results in only minor

injuries and no information about the

weapon is recorded, then it may be

misclassified as a simple assault.

NIBRS restructures assault into three

categories: aggravated, simple, and

intimidation. The collection of these

characteristics by incident and a

broader collection of weapon information reduce the possibility of misclassification. 

Expanding the hotel rule for NIBRS

had more impact on crime statistics.

The hotel rule applies to “[b]urglaries 

of hotels, motels, lodging houses, and

other places where lodging of

transients is the main purpose . . . This

principle of scoring dictates that if a

number of dwelling units under a single

manager are burglarized and the

offenses are most likely to be reported

to the police by the manager rather

than the individual tenants, the burglary

should be scored as one offense.”3

NIBRS expands the hotel rule to

include temporary rental storage facilities, such as “mini-storage” and “selfstorage” buildings.4

 If some ministorage lockers under the same

management are broken into,

Summary UCR would count each as a

separate burglary whereas NIBRS

could count them as one. The lower

burglary rates in NIBRS indicate the

frequency of this type of break-in.

Distributions

For total Index crime, the distribution of

rate changes shows that 92.5% of the

cases have rate difference between

-0.5% and 15.5% (figure 3). Burglary

rates that were lower in NIBRS than in

Summary UCR could influence total

property and total Index crime rates to

the degree that they also could have

negative values. Almost 48% of the

cases differed from -0.5% to +0.5% in

crime rates, comparing NIBRS to

Summary UCR; 39% of all cases had

no change. Cases whose rate was

lower when comparing NIBRS counts

to Summary UCR counts comprised

4.9% of all cases studied. Overall,

96.4% of all cases had an index crime

rate difference of +15.5% or less.

For violent crime, the distribution of

rate differences show that 98.9% of

cases have differences between 0 and

15.5% for total violent crime (figure 4).

Cases with a difference from 0 to 0.5%

were 84.3% of the total; 82.2% of all

cases had no difference. 

For total property crime, rates were

-0.5% to +15.5% higher for 91.7%. 

In 48% of the cases the difference

between the rates resulting from the

two reporting systems was -0.5% to

0.5%, 40.1% of all cases having no

difference. Cases whose rate was

lower when comparing NIBRS counts

to Summary UCR counts comprised

5.1% of all cases studied. Overall, a

total of 95.8% of cases showed a

property crime rate difference of

+15.5% or less. 

 Effects of NIBRS on Crime Statistics 5

0 1% 2% 3% 4% 5% 6% 7% 8% 9% 10% 11% 12% 13% 14% 15%

0

500

1,000

1,500

2,000

2,500

3,000

3,500

Number of cases

Violent

Property

Rounded percent difference when comparing NIBRS to Summary UCR

The rates of violent crime from Summary UCR and NIBRS differed 0.5% or less 

in over 84% of the cases

Figure 3

0 1% 2% 3% 4% 5% 6% 7% 8% 9% 10%11%12%13%14%15%

0

500

1,000

1,500

2,000

Number of cases

Rounded percent difference when comparing NIBRS to Summary UCR

There was a difference of 2.5% or less between Summary UCR and NIBRS 

in the Index crime rate in over three-quarters of the cases

Figure 4

3

FBI, UCR Handbook, 1984, p.20.

4

FBI, UCR Handbook, NIBRS ed., 1992, p.13.
Jurisdictions with a population

greater than 25,000

The largest jurisdictions in the dataset

(1991-96) covered populations

between 25,000 and 250,000. The

overall results of the 378 cases from

these larger jurisdictions are very

similar to the results from all jurisdictions studied (the original 4068 cases).

The Index crime rate for NIBRS was

about 2% higher than for Summary

UCR (figure 5). The NIBRS violent

crime rate was higher by less than 1%,

and the NIBRS property crime rate was

higher by slightly more than 2%, on

average. Murder rates from NIBRS

and Summary UCR were the same.

The average difference in rates for

rape from the two systems was slightly

more than 1%. Robbery and aggravated assault rates were higher by an

average of less than 1%, going from

Summary UCR to NIBRS. 

NIBRS burglary rates were lower by

an average of slightly more than 1%.

NIBRS larceny rates were higher than

those from Summary UCR by slightly

over 3%, and NIBRS motor vehicle

theft rates, higher by just over 4%, on

average.

The distribution of the rate differences

for large jurisdictions was also similar

to the results of all jurisdictions studied.

Among cases from large jurisdictions,

92.3% had a difference of 5.5% or less

(including any lower rates) in the total

index crime rate, as measured by

Summary UCR and NIBRS (table 4).

Among cases from jurisdictions with

nonzero populations, 90.0% had a

negligible difference. 

The distribution within this range was

spread out. For example, 31.5% of

these cases experienced an Index

crime rate difference from -0.5% to

0.5%. A few large jurisdictions (6.3%)

showed no difference, and in 9.8% of

the cases the Index crime rate was

lower using NIBRS data.

The proportion of cases with a violent

crime rate change of 5.5% or less is

98.4% for large jurisdictions. More

than half of the large jurisdictions had a

higher rate in 0.5% or less of cases.

Nearly 40% experienced no change in

the violent crime rate when using

NIBRS rather than Summary UCR.

Among cases from populations 25,000

or over, 93.1% experienced a property

crime rate change of 5.5% or less,

compared to 89.6% of all cases with

nonzero populations (table 5). The

property crime rate did not differ for

nearly 8% and was lower for more than

10% of the large jurisdictions.

Although a smaller proportion of large

jurisdictions had no change at all, and

a higher proportion showed lower rates

compared to all nonzero populations,

similar proportions had a 5.5% 

or less difference in rates, comparing

results from NIBRS and Summary

UCR. The same pattern holds true 

for proportions of jurisdictions with a

15.5% or less change in rates.

Results for specific crime

categories, 1996

Rates for larceny and motor vehicle

theft were found to be substantially

higher and that for aggravated assault,

a slightly higher, comparing NIBRS to

Summary UCR. The 1996 NIBRS

incident file was analyzed to see what

characteristics coincided with these

higher rates. Incidents with more than

one victim and/or more than one

offender were excluded from this

analysis.

6 Effects of NIBRS on Crime Statistics 

-2% 0 1% 3% 5%

Property offenses

Violent offenses

Index crimes

Larceny

Motor vehicle theft

Burglary

Aggravated assault

Robbery

Rape

Murder

Offenses in jurisdictions larger than 25,000 

Average percent difference in 

crime rates when reported through

NIBRS rather than Summary UCR

NIBRS and Summary UCR differed 

an average of less than 1% for 

violent crime rates and about 

2% for property crime rates 

33.8% 37.5% 4.7% 25.0% 64.9%

Highest percent

difference

Exactly 0% 6.3% 7.9% 24.6% 23.0% 12.2%

Over 5.5% 7.7 8.2 0.0 30.7 11.4

1.6% to 5.5% 15.8 18.0 10.6 36.2 16.6

0.6% to 1.5% 39.2 34.1 23.5 9.3 30.2

-0.5% to 0.5% 31.5 33.6 37.6 23.8 41.8

-1.5% to -0.6% 3.2 2.6 7.1 0.0 0.0

-5.5% to -1.6% 5.3 2.9 11.7 0.0 0.0

Under -5.5% 0.5% 0.5% 9.5% 0.0% 0.0%

Larceny

Motor

vehicle theft

BurglaryProIndex pertydifference in

the crime rate

Percent Percent of cases

Table 5. Difference in the property crime rate 

comparing NIBRS and Summary UCR estimates 

for jurisdictions with 25,000 to 250,000 population

33.8% 10.0% 0.0% 50.0% 22.2% 11.4%

Highest percent

difference

Exactly 0% 6.3% 39.2% 100.0% 84.1% 69.8% 51.6%

Over 5.5% 7.7 1.6 0.0 7.1 4.2 2.4

1.6% to 5.5% 15.8 17.4 0.0 8.0 13.5 14.8

0.6% to 1.5% 39.2 29.1 0.0 0.8 10.8 16.9

-0.5% to 0.5% 31.5 51.9 100.0 84.1 71.4 65.9

-1.5% to -0.6% 3.2 0.0 0.0 0.0 0.0 0.0

-5.5% to -1.6% 5.3 0.0 0.0 0.0 0.0 0.0

Under -5.5% 0.5% 0.0% 0.0% 0.0% 0.0% 0.0%

 

Assault

Robbery

 

Rape

MurderVioIndex lentdifference in 

the crime rate

Percent Percent of cases

Table 4. Difference in the violent crime rate comparing

NIBRS and Summary UCR estimates for jurisdictions 

with 25,000 to 250,000 population 

Figure 5
Larceny

There were 381,233 incidents in the

study data with at least one count of

larceny in NIBRS in 1996 (table 6).

These can be broken into two

categories: 369,690 single-offense

incidents and 11,543 multiple-offense

incidents. Of the multiple-offense

incidents, 9,601 had a combination 

of 1 or 2 larcenies and at least 1 other

Index crime. The remaining 1,942

multiple-offense incidents involved 2 or

3 counts of larceny and no other Index

crime.

Under the hierarchy rule of the

Summary UCR, the incidents

involving only larceny would

each be counted as one

incident, regardless of whether

there were multiple larcenies.

Because larceny is at the

bottom of the hierarchy, the

9,601 multiple-offense incidents

involving larceny and another

Index crime would be counted

under the concurrent Index

crime, not the larceny. 

From the above figures for

1996, 371,632 incidents

including larceny were counted

under Summary UCR. Under

the NIBRS system the number

of incidents involving larceny

increased 2.6%. This higher

rate can be attributed to the

hierarchy rule.

The total counts of larceny

under NIBRS would be 383,256

(the number of incidents

involving 1 larceny, plus twice

the number of incidents

involving 2 larcenies, plus 3

times the number of incidents

involving 3 larcenies,

regardless of what other Index

crimes may have been

concurrent). Under Summary

UCR, due to the hierarchy rule,

the number of counts of larceny

equals the number of incidents

that involve only larceny. There

was a 3.1% difference between

NIBRS larceny counts and

Summary UCR larceny counts.

This 0.5% higher level over the number

of incidents was due to the reporting

of multiple counts of larceny within an

incident. Three of the nine States with

NIBRS data had a disproportionate rise

in larceny rates. The three States

together accounted for 17% of all

larcenies, but for 80% of the burglarylarceny combinations and for 65% 

of the larceny-larceny combinations.

While the average percent difference 

in larceny rates for all nine States was

3.4%, the average for the three States

was 19.1% (not shown in a table).

In multiple-offense incidents some

records from the three States included

larceny segments contrary to FBI

instructions. For example, the FBI

defines burglary as breaking and

entering with intent to commit a felony

or theft. Theft is included in the

definition of burglary and should not be

reported as a concurrent larceny.

5

In the 1996 data, more than 8,200

incidents were recorded as

 Effects of NIBRS on Crime Statistics 7

Note: To determine the number of incidents involving a specific type of crime, add the 

figures found in each row and column listing that offense. For example, robbery occurs 

in 6,277 incidents: 5,829 single-, 420 double-, 26 triple-, and 1 quadruple-offense incidents. 

*Lesser offenses for incidents with more than two offenses.

Percent difference 0.00% 0.05% 1.00% 0.42% 0.52% 2.5% 3.13% 2.37%

NIBRS 441 4,314 6,277 36,110 105,852 40,667 383,256 576,917

Summary UCR 441 4,312 6,215 35,958 105,305 39,677 371,632 563,540

Total offense counts

NIBRS 30 246 448 725 9,453 2,106 11,543 24,551

Total multiple-offense incidents

Percent difference 0.00% 0.05% 1.00% 0.42% 0.52% 2.50% 2.58% 2.01%

NIBRS 441 4,314 6,277 36,110 105,852 40,667 381,233 574,894

Summary UCR 441 4,312 6,215 35,958 105,305 39,677 371,632 563,540

Total incidents 

1 * * * 1

Aggravated assault, 

burglary, motor vehicle theft

Four

Larceny, larceny 62 15 4 81

Motor vehicle theft, larceny 1 1 44 * * 46

Burglary, larceny 5 4 12 * * 21

Burglary, motor vehicle theft 1 5 * * 6

Aggravated assault, larceny 1 * * 1

3 * * 3

Aggravated assault, motor

vehicle theft

Aggravated assault, burglary 7 2 * * 9

Robbery, motor vehicle theft 2 1 * * 3

Robbery, burglary 6 * * 6

Robbery, aggravated assault 2 * * 2

Three

Larceny 0 18 35 225 8,077 1,101 1,938 11,394

Motor vehicle theft 5 5 157 41 723 0 931

Burglary 4 104 102 294 0 504

Aggravated assault 3 58 75 0 136

Robbery 14 37 0 51

Rape 2 0 2

Murder 0 0

Two

One 411 4,068 5,829 35,385 96,399 38,561 369,690 550,343

Larceny Total

Motor 

vehicle 

Burglary theft

Aggravated 

Murder Rape Robbery assault

Number of 

offenses 

in incident

Type of crime

Table 6. Number of incidents, by type of crime and concurrent offense(s), 

single victim, single offender

5

FBI, Uniform Crime Reporting Handbook,

NIBRS edition, 1992, p. 13.
burglary-larceny combinations.

Though a small number of these may

have included a count of larceny

distinctly separate from the burglary,

the majority of these should have been

recorded as burglary only. 

These States have penal codes with

reporting implications that differ from

FBI standards. Some State penal

codes define burglary as breaking and

entering only and mandate recording

larceny if property was stolen. Others

mandate recording every crime an

arrestee might be charged with. 

As a consequence, the crime rates

produced by NIBRS in these States 

are erroneously inflated. 

Motor vehicle theft

In the 1996 NIBRS incident file, there

were 40,667 incidents involving motor

vehicle theft; 38,561 were singleoffense incidents. There were 2,106

multiple-offense incidents that involved

a single motor vehicle theft and 1 or

more other Index crimes: 1,162

involved larceny, 774 involved burglary,

and 44 involved all 3 property crimes

(burglary, larceny, and motor vehicle

theft). Two hundred twenty-three

incidents of motor vehicle theft involved

one or more violent offenses. 

A total of 990 incidents involved motor

vehicle theft and what Summary UCR

would classify as a more serious

offense, so that approximately 2.4% of

the motor vehicle thefts would have

been suppressed by the hierarchy rule.

Some agencies ranked larceny above

motor vehicle theft in the hierarchy.

However, incidents involving both

motor vehicle theft and larceny are

classified as motor vehicle theft in

Summary UCR.7

 These agencies

would also show more motor vehicle

thefts after correction of this reporting

error.

Aggravated assault

There were 36,110 incidents involving

aggravated assault in the data file. 

Of these, 35,385 were single-offense

incidents. The 725 multiple-offense

incidents involved 1 count of aggravated assault and at least 1 other Index

crime. 

In 152 multiple-offense incidents an

aggravated assault was recorded with

at least 1 other violent crime. These

cases comprised 0.4% of all aggravated assaults and would be

suppressed by the hierarchy rule in

Summary UCR reporting. Eighty-four

multiple-offense incidents involved both

aggravated assault and robbery.

Because incidents with only one victim

and one offender were selected, and

assault is one element of robbery,

reporting both appears to be either an

error or another indication of the

influence of State penal code on

classification for UCR data. 

There were 185,408 incidents involving

one or more types of assault, 184,357

with a single count of aggravated

assault, simple assault, or intimidation.

When multiple-offense cases were

selected in the manner described

above, 1,051 incidents had some

combination of aggravated assault,

simple assault, and intimidation. There

were 658 incidents of aggravated

assault with at least 1 lesser assault,

and 393 incidents of simple assault

with intimidation. 

8 Effects of NIBRS on Crime Statistics 

Larceny, larceny 15

Burglary, larceny 44

Larceny 1,101

Burglary 723

Property

1

Robbery, aggravated

assault, burglary

Assault, larceny 1

Robbery, larceny 1

Robbery, burglary 5

3

Robbery, aggravated

assault

Rape, burglary 1

Violent and property

Rape, robbery 1

Murder, robbery 2

Assault 41

Robbery 157

Rape 5

Murder 5

Violent 

Total 2,106

Number of

incidents

Index crime combinations

for 1 victim, 1 offender

Motor vehicle theft

Simple, intimidation 393

43

Aggravated, simple, 

intimidation

Aggravated, intimidation 222

Aggravated, simple 393

Intimidation 30,454

Simple 118,451

Aggravated 35,452

Total 185,408

Number 

of 

incidents

Combination of assaults that

occurred in incidents with 

one or more assaults

for 1 victim, 1 offender

Motor vehicle theft, larceny 3

Burglary, larceny 10

Larceny 225

Motor vehicle theft 41

Burglary 294

Property

1

Robbery, burglary, motor

vehicle theft

Robbery, larceny 1

Robbery, motor vehicle theft 3

Robbery, burglary 2

Rape, burglary 7

Violent and property

Rape, robbery 2

Robbery 75

Rape 58

Murder 3

Violent 

Total 725

Number of

incidents

Index crime combinations 

for 1 victim, 1 offender

Aggravated assault

7

FBI, Uniform Crime Reporting Handbook, 1984,

p. 35.
There were 1,072 incidents involving

larceny and at least 1 type of assault.

Of these, 226 involved an aggravated

assault and larceny; 13 involved

aggravated assault, at least 1 lesser

assault, and larceny; and 833 involved

1 or 2 lesser assaults and larceny.

Conclusion

Because of the selection criteria and

the voluntary nature of UCR reporting,

the cases in this analysis do not

constitute a random sample. Although

one must be careful in drawing

conclusions on a national level, there is

no reason to believe the results are

skewed. The large sample size (1,131

jurisdictions, 4,068 cases) suggests

that results may be applicable to

similar jurisdictions.

To accurately compare NIBRS and

Summary UCR data, several factors

need to be considered: artifactual

differences, non-uniform reporting

practices, and reporting errors.

Artifactual differences between the two

reporting systems include expansion 

of the hotel rule and modified or

restructured crime definitions in

NIBRS, and the use of the hierarchy

rule in Summary UCR. 

By design NIBRS measures different

aspects of crime than Summary UCR.

Where Summary UCR measures the

overall number of incidents for an index

of crime, NIBRS measures both the

overall number of incidents and the

occurrence of each type of crime within

every incident. NIBRS reporting gives

more detail about offenses that occur

during the commission of a crime

without reporting significantly higher

crime rates in most cases. However,

NIBRS is more prone to non-uniform

reporting practices and programming

errors, whereas Summary UCR is

more prone to reporting errors.

Analysis for this report identified 

several instances of non-uniform

reporting practices. After 1996 the FBI

began a series of data edits to help

reconcile some of those practices.

These edits, which were not in place at

the time the data used in this research

were collected, identify crime

combinations that do not comply with

FBI reporting standards. A chart

denoting these combinations on page

115 of Uniform Crime Reporting

National Incident-Based Reporting

System, Volume 4, Error Message

Manual is reproduced in appendix table

3. Incident reports that contain any of

the indicated combinations (occurring

to the same victim) are sent back to

the reporting agency for correction. 

The data edits do not cover the

non-uniform reporting practices that

had the most impact on the crime

statistics in this study. For example,

although a combination of burglary and

larceny in a single incident is contrary

to FBI standards, this combination is

not included in the data edits because

the FBI makes an allowance for the

rare occasion in which this combination

may legitimately be reported. This

study found this combination in certain

jurisdictions because the State or local

penal code required it. Consequent to

this study the FBI began addressing

this issue in its State-level training

program.

It is important for jurisdictions to collect

and maintain data in compliance with

their penal codes. Uniformity is also

critical for data submitted for reporting

at the national level. Many States have

worked on developing a software

program that can automatically convert

the crime codes as defined by State

penal codes to the appropriate NIBRS

crime code. At least one State has

successfully implemented an

automated State-to-NIBRS crime code

conversion system. Others have been

unsuccessful due to State codes

overlapping more than one NIBRS

code. In these cases, the conversion

is done manually while the States

develop new programs capable of

distinguishing the complex codes.

 

As noted in pages 2 and 8, the

reporting errors in Summary UCR

identified in this report occur largely

from undercounting aggravated assault

and misapplying the hierarchy rule for

motor vehicle theft. Further study is

required to determine how much

impact the misapplication of the

hierarchy rule has on motor vehicle

theft and larceny statistics. The design

of NIBRS automatically reduces this

type of reporting error. As States and

jurisdictions are made aware of these

potential errors in Summary UCR

reporting, they can be corrected before

switching to NIBRS. 

Another concern not addressed by this

analysis is the effect NIBRS reporting

might have on the rate of aggravated

assault. The effects of misclassifying

aggravated assaults as simple assault

depend on the proportion of

misclassified aggravated assaults. To

study such effects requires having the

original Summary UCR reported by an

agency. BJS had NIBRS data that had

been converted to Summary UCR.

It is not meaningful to compare

Summary UCR data from one year to

NIBRS data from another. When the

two reporting methods are compared

within a given year, external variables

are controlled for. When one year of

data is compared to another, many

more variables, such as the prevalence

and reporting of crime, or errors in

applying the hierarchy rule are

introduced. Not all of these variables

can be identified or measured,

compounding the error in the results.

After several years of NIBRS data have

been collected, it would then be more

meaningful to compare one year of

NIBRS data to another. 

 Effects of NIBRS on Crime Statistics 9

Simple, intimidation 3

Aggravated, simple, 1

intimidation

Aggravated, intimidation 1

Aggravated, simple 11

Intimidation 123

Simple 707

Aggravated 226

Total 1,072

Number 

of 

incidents

Combination of assaults that 

occurred in incidents with 

larceny for 1 victim, 1 offender
The FBI has begun publishing a series

of topical studies using NIBRS data.

The first one, “Juvenile Female Crime:

A Special Study” appeared in Crime in

the United States, 1997, section V; 

“Incidents of Family Violence”

appeared in the 1998 report. Studies

covering various topics will be

published in other sections of Crime 

in the United States in future years.

For the more expansive tables, the FBI

currently publishes statistics using only

Summary UCR data and NIBRS data

that have been converted back to

Summary UCR. They are preparing a

report that compares data submitted 

in Summary UCR format to data

submitted in NIBRS. Plans for a

NIBRS publication comparable to

Crime in the United States are under

development.

Methodology

For comparisons the rate per 100,000

population was calculated for each

crime category in each case. For a

positive percent change to indicate that

the NIBRS rate is higher than the

corresponding Summary UCR rate, the

following formula was used.

 100 x (NIBRS Rate - Summary UCR Rate)

 Summary UCR Rate

In a small number of cases for specific

offenses the Summary UCR count was

zero, and the NIBRS count was greater

than zero. The resulting percent

difference was mathematically

undefined. These cases were included

in the denominators in the calculation

of percentages of cases. 

 

Negative changes, indicating that the

NIBRS rate is lower than the

corresponding Summary UCR rate, are

possible for burglary (and consequently

for total property crime and total index

crime) due to the expansion of the

hotel rule in NIBRS. 

To clearly see the effect of NIBRS on

the crime rates of larger jurisdictions,

the same analysis was done using a

subset of these 4,068 cases.

Jurisdictions with populations over

25,000 and that were not combined

reporters were selected. Combined

reporters are agencies that report data

for at least one other jurisdiction in

addition to their own. To ensure this

analysis included only jurisdictions with

populations over 25,000, combined

reporters were excluded. 378 cases

were selected. None of the

jurisdictions reporting NIBRS data

between 1991 and 1996 covered

populations over 250,000.

10 Effects of NIBRS on Crime Statistics 

The Bureau of Justice Statistics 

is the statistical agency of the 

U.S. Department of Justice. 

Jan M. Chaiken, Ph.D., is director.

BJS Special Reports address a

specific topic in depth from one or

more data sets that cover many

topics.

Ramona Rantala, BJS Statistician,

wrote this report. Thomas Edwards,

FBI Systems Analyst, assisted with

the assembling of NIBRS data and

converting to the Summary UCR

format. Victoria Major, Yoshio

Akiyama, Sharon Propheter, James

Nolan, and Christopher Enourato, 

all FBI CJIS staff, assisted with

reviewing this report. Tom Hester

edited and produced the report,

assisted by Ellen Goldberg. Jayne

Robinson produced the report for

final printing.

July 2000, NCJ 178890

This report and related reports and

statistics can be obtained from the

Internet at http://www.ojp.usdoj.

gov/bjs/

Data presented in this report can be

obtained from the National Archive

of Criminal Justice Data (NACJD) 

at the University of Michigan. The

Archive can be reached through 

the BJS website or by telephone,

1-800-999-0960. The study number

for NIBRS data at NACJD is 2465.
 

 Effects of NIBRS on Crime Statistics 11

90F Liquor law violations

90E Drunkenness 90Z All other offenses

90D Driving under the influence 90J Trespassing

90C Disorderly conduct 90I Runaways

90B Curfew/loitering/vagrancy 90H Peeping Tom

90A Bad checks 90G Nonviolent family offenses

Group B offenses

520 Weapon law violations

280 Stolen property offenses

36B Statutory rape

36A Incest

Sex offenses, nonforcible

11D Forcible fondling

11C Sexual assault with an object

26 All other offenses (except traffic) 11B Forcible sodomy

29 Runaways 11A Forcible rape

28 Curfew and loitering law violations Sex offenses, forcible

27 Suspicion 120 Robbery

25 Vagrancy 40B Assisting or promoting prostitution

24 Disorderly conduct 40A Prostitution

23 Drunkenness Prostitution offenses

22 Liquor laws 370 Pornography/obscene material

21 Driving under the influence 240 Motor vehicle theft

20 Offenses against family and children 23H All other larceny

19C All other gambling 23G Theft of motor vehicle parts/accessories

19B Numbers and lottery 23F Theft from motor vehicle

19A Bookmaking (horse and sport book) 23E Theft from coin-operated machines

190 Gambling 23D Theft from building

18H Other & dangerous nonnarcotic drugs 23C Shoplifting

18G Synthetic narcotics 23B Purse snatching

18F Marijuana 23A Pocket picking

18E Opium or cocaine and their derivatives Larceny/theft offenses

185 Possession 100 Kidnaping/abduction

18D Other & dangerous nonnarcotic drugs 09C Justifiable homicide

18C Synthetic narcotics 09B Negligent manslaughter

18B Marijuana 09A Murder/nonnegligent manslaughter

18A Opium or cocaine and their derivatives Homicide offenses

180 Sale/manufacturing 39D Sports tampering

18 Drug abuse violations 39C Gambling equipment violations

17 Sex offenses (except forcible rape and prostitution) 39B Operating/promoting/assisting gambling

16 Prostitution and commercial vice 39A Betting/wagering

15 Weapons: carrying, possessing, other Gambling offenses

14 Vandalism 26E Wire fraud

13 Stolen property: buying, receiving, possessing 26D Welfare fraud

12 Embezzlement 26C Impersonation

11 Fraud 26B Credit card/ATM fraud

10 Forgery and counterfeiting 26A False pretenses/swindle/confidence game

08 Other assaults Fraud offenses

Code Offense 210 Extortion/blackmail

270 Embezzlement

Part II offenses 35B Drug equipment violations

35A Drug/narcotic violations

09 Arson Drug/narcotic offenses

07 Motor vehicle theft 290 Destruction/damage/vandalism of property

06 Larceny & theft (except motor vehicle theft) 250 Counterfeiting/forgery

05 Burglary & breaking or entering 220 Burglary/breaking and entering

04 Aggravated assault 510 Bribery

03 Robbery 13C Intimidation

02 Forcible rape 13B Simple assault

012 Manslaughter by negligence 13A Aggravated assault

011 Murder and nonnegligent manslaughter Assault offenses

Criminal homicide offenses 200 Arson

Code Offense Code Offense

Part I (Index) offenses Group A offenses & Index offenses in bold

Summary UCR NIBRS

Appendix table 1. Specific crimes and their offense/arrest codes, Summary UCR and NIBRS 

Summary UCR collects offense information for Index offenses (subject to hierarchy rule) and arrest information for all

Part I and Part II offenses. NIBRS collects detailed offense information on each occurrence of crimes listed under

Group A offenses and arrest information for all Group A and Group B offenses. 
12 Effects of NIBRS on Crime Statistics 

In any instance of robbery, score one offense for each distinct operation including attempts. Do not count the number of victims

robbed, those present at the robbery, or the number of offenders. In cases involving pretended weapons or those in which the

weapon is not seen by the victim but the robber claims to possess one, classify the incident as armed robbery.

Robbery: The taking, or attempting to take, anything of value

under confrontational circumstances from the control, custody,

or care of another person by force or threat of force or violence

and/or by putting the victim in fear of immediate harm.

Because some type of assault is an element of the crime of

robbery, an assault should not be reported as a separate crime

as long as it was performed in the furtherance of the robbery.

However, if the injury results in death, a homicide offense must

also be reported.

Robbery: The taking or attempting to take anything of value

from the care, custody, or control of a person or persons by

force or threat of force or violence and/or by putting the victim 

in fear.

a) firearm

b) knife or cutting instrument

c) other dangerous weapon

d) strong-arm – hands, fists, feet, etc.

Robbery

In cases where several offenders rape one person, report one forcible rape. Do not count the number of offenders. Assaults or

attempts to commit rape by force or threat of force are also included; however, statutory rape (without force) and other sex

offenses are excluded from this classification.

Forcible rape: The carnal knowledge of a person, forcibly,

and/or against that person’s will; or not forcibly or against the

person’s will where the victim is incapable of giving consent

because of his/her temporary or permanent mental or physical

incapacity (or because of his/her youth).

Includes male and female victims. Cases where victim and

offender are of the same sex are classified under forcible

sodomy.

Forcible rape: The carnal knowledge of a female forcibly and

against her will.

a) rape by force

b) attempts to commit forcible rape

Includes female victims only.

Forcible rape

Forcible sex offenses: Any sexual act directed against another

person, forcibly, and/or against that person’s will; or not forcibly

or against the person’s will where the victim is incapable of

giving consent. Forcible rape, forcible sodomy, sexual assault

with an object, and forcible fondling are included in this

category.

Forcible sex 

offenses (NIBRS)

Justifiable homicide: The killing of a perpetrator of a serious

criminal offense by a peace officer in the line of duty; or the

killing, during the commission of a serious criminal offense, of a

perpetrator by a private individual 

Justifiable homicide is not an actual “offense” and is not

included in an agency’s crime counts. The crime that was being

committed when the justifiable homicide took place must be

reported as a separate incident.

Justifiable homicide: The killing of a felon by a peace officer

in the line of duty, or the killing (during the commission of a

felony) of a felon by a private citizen. 

Recorded as murder and then unfounded, no actual offenses

will be counted or recorded for justifiable homicides.

In cases of justifiable homicide, a second offense, the crime 

the felon was committing at the time of death, must also be

recorded and cleared by exceptional means.

Not included in this category are deaths of persons due to their own negligence; accidental deaths not resulting from gross

negligence.

Negligent manslaughter: The killing of another person through

negligence.

Does not include accidental traffic fatalities.

Manslaughter by negligence: The killing of another person

through gross negligence.

Does not include traffic fatalities. However, arrests in connection with traffic fatalities should be counted on the Age, Sex,

Race, and Ethnic Origin of Persons Arrested form as

manslaughter by negligence.

As a general rule, any death due to injuries received in a fight, argument, quarrel, assault, or commission of a crime is classified

in this category. Although offenders may be charged with lesser offenses, e.g., manslaughter, if the killing was “willful” or intentional it must be reported in this category.

Murder and nonnegligent manslaughter: The willful (nonnegligent) killing of one human being by another.

Murder and nonnegligent manslaughter: The willful 

(nonnegligent) killing of one human being by another.

Also excluded in the count for this offense classification are

deaths caused by justifiable homicides, which are recorded as

murder and then unfounded.

The classification of this offense, as for all other Crime Index offenses, is based solely on police investigation as opposed to the

determination of a court, medical examiner, coroner, jury, or other judicial body; these are law enforcement statistics. Not

included in the count for this offense classification are deaths caused by negligence, suicide, or accident; and attempts to murder

or assaults to murder, which are scored as aggravated assaults.

Homicide

NIBRSb Summary UCRa Offense

Appendix Table 2. Summary UCR and NIBRS offense classifications
 

 Effects of NIBRS on Crime Statistics 13

Theft from motor vehicle: The theft of articles from a motor

vehicle, whether locked or unlocked.

Thefts from motor vehicles: Except theft of motor 

vehicle parts and accessories, the theft of articles from a

motor vehicle, whether locked or unlocked.

Shoplifting: The theft, by someone other than an employee of

the victim, of goods or merchandise exposed for sale.

Shoplifting: The theft by a person (other than an 

employee) of goods or merchandise exposed for sale.

Purse-snatching: The grabbing or snatching of a purse,

handbag, etc., from the physical possession of another person.

Purse-snatching: The grabbing or snatching of a purse,

handbag, etc. from the custody of an individual.

Pocket-picking: The theft of articles from another person’s

physical possession by stealth where the victim usually does not

become immediately aware of the theft.

Pocket-picking: The theft of articles from a person by

stealth where the victim usually does not become immediately

aware of the theft.

Larceny and theft mean the same thing in Uniform Crime Reporting. Motor vehicle theft is not included and is counted as a

separate offense because of the great volume of thefts in that particular category. All thefts and attempted thefts are counted.

This crime category does not include embezzlement, confidence games, forgery, and worthless checks.

Larceny: The unlawful taking, carrying, leading, or riding away

of property from the possession, or constructive possession, of

another person.

Larceny: The unlawful taking, carrying, leading, or riding

away of property from the possession, or constructive possession, of another.

Larceny

Burglaries of hotels, motels, lodging houses, and other places where lodging of transients is the main purpose are scored under

provisions of the “Hotel Rule.” This principle of scoring dictates that if a number of dwelling units under a single manager are

burglarized and the offenses are most likely to be reported to the police by the manager rather than the individual tenants, the

burglary should be scored as one offense.

Burglary: The unlawful entry into a building or other structure

with the intent to commit a felony or a theft (excludes tents, trailers, and other mobile units used for recreational purposes).

Because burglary is defined in terms of theft, only the burglary is

to be reported, and not the accompanying larceny.

Expands the hotel rule to include temporary rental storage facilities, i.e., “mini-storage” and “self-storage” buildings.

Burglary: The unlawful entry of a structure to commit a

felony or a theft (excludes tents, trailers, and other mobile

units used for recreational purposes).

The use of force to gain entry is not required to classify

an offense as burglary. Burglary in this Program is 

categorized into three subclassifications:

a) forcible entry

b) unlawful entry – no force

c) attempted forcible entry

Burglary

Simple assault: An unlawful physical attack by one person

upon another where neither the offender displays a weapon, nor

the victim suffers obvious severe or aggravated bodily injury

involving apparent broken bones, loss of teeth, possible internal

injury, severe laceration or loss of consciousness.

Intimidation: To unlawfully place another person in reasonable

fear of bodily harm through the use of threatening words and/or

other conduct, but without displaying a weapon or subjecting the

victim to actual physical attack.

Other assault: e) other – simple, not aggravated

Include in this category all assaults which do not involve 

the use of a firearm, knife, cutting instrument, or other

dangerous weapon and in which there were no serious or

aggravated injuries to the victims. Include such offenses 

as simple assault, assault and battery, injury caused by culpable negligence, intimidation, coercion, and all attempts to

commit these offenses.

Simple assault is not within the Crime Index – it is a Part II

offense but is collected as a quality control matter and for the

purpose of looking at total assault violence.

It is not necessary that an injury result when a gun, knife, or other weapon is used which could and probably would result in

serious personal injury.

Aggravated assault: An unlawful attack by one person upon

another wherein the offender uses a weapon or displays it in a

threatening manner, or the victim suffers obvious severe or

aggravated bodily injury involving apparent broken bones, loss

of teeth, possible internal injury, severe laceration, or loss of

consciousness. This also includes assault with disease (as in

cases when the offender is aware that he/she is infected with a

deadly disease and deliberately attempts to inflict the disease by

biting, spitting, etc.).

Aggravated assault: An unlawful attack by one person upon

another for the purpose of inflicting severe or aggravated

bodily injury; this type of assault usually is accompanied by

the use of a weapon or by means likely to produce death or

great bodily harm.

a) firearm

b) knife or cutting instrument

c) other dangerous weapon

d) hands, fists, feet, etc. (aggravated injury)

e) other – simple, not aggravated (see below)

Assault Assault: An unlawful attack by one person upon another. Assault: An unlawful attack by one person upon another.

NIBRSb Summary UCRa Offense

Appendix Table 2. Continued
 

14 Effects of NIBRS on Crime Statistics 

b

Uniform Crime Reporting Handbook NIBRS Edition, FBI, 1992; and Uniform Crime Reporting, National Incident-Based 

Reporting System, Volume 1, Data Collection Guidelines, FBI, 1996.

a

Uniform Crime Reporting Handbook. FBI, 1984; and Crime in the United States, 1998. FBI, 1999.

Other motor vehicles: Any other motor vehicles, e.g., motorcycles, motor scooters, trail bikes, mopeds, snowmobiles, golf

carts, whose primary purpose is to transport people.

Other vehicles: All other vehicles limited by the UCR definition, such as snowmobiles, motorcycles, motor scooters, trail

bikes, mopeds, golf carts, etc.

Recreational vehicles: Motor vehicles that are specifically

designed (but not necessarily used) to transport people and also

provide them temporary lodging for recreational purposes.

Recreational vehicles are included with trucks and buses.

Trucks: Motor vehicles that are specifically designed (but not

necessarily used) to transport cargo on a commercial basis.

Buses: Motor vehicles that are specifically designed (but not

necessarily used) to transport groups of people on a commercial

basis.

Trucks and buses: Vehicles specifically designed to transport people on a commercial basis and to transport cargo;

includes pickup trucks and vans regardless of their use; in

UCR the self-propelled motor home is a truck.

Automobiles: Sedans, coupes, station wagons, convertibles,

taxicabs, or other similar motor vehicles that serve the primary

purpose of transporting people.

Autos: All sedans, station wagons, coupes, convertibles, and

other similar motor vehicles that serve the primary purpose of

transporting people from one place to another; also include

automobiles used as taxis.

Motor vehicle theft includes joyriding, excludes the taking of a motor vehicle for temporary use by those persons having lawful

access. A “motor vehicle” is defined for UCR purposes as a self-propelled vehicle that runs on land surface and not on rails.

This offense category includes the stealing of automobiles, trucks, buses, motorcycles, motor scooters, snowmobiles, etc. It

does not include farm equipment, bulldozers, airplanes, construction equipment, or motorboats.

Motor vehicle theft: The theft or attempted theft of a motor Motor vehicle theft: The theft of a motor vehicle.

vehicle.

Motor vehicle 

theft

All other larceny: All thefts that do not fit any of the definitions

of the specific subcategories of Larceny/Theft listed above.

All other larceny - theft not specifically classified: All

thefts that do not fit the definition of the specific categories of

larceny listed above.

Theft from coin-operated machine or device: A theft from a

machine or device that is operated or activated by the use of

coins.

Thefts from coin-operated device or machine: A theft from 

a device or machine which is operated or activated by the 

use of a coin.

Theft from building: A theft from within a building that is either

open to the general public or where the offender has legal

access.

Thefts from buildings: A theft from within a building that is

open to the general public and where the offender has legal

access.

h

Theft of bicycles: NIBRS does not classify theft of bicycles as

a separate type of larceny. Bicycles can be identified by the

Property Type data element.

Thefts of bicycles: The unlawful taking of any bicycle,

tandem bicycle, unicycle, etc.

Theft of motor vehicle parts or accessories: The theft of any

part or accessory affixed to the interior or exterior of a motor

vehicle in a manner that would make the item an attachment of

the vehicle or necessary for its operation.

Theft of motor vehicle parts and accessories: The theft 

of any part or accessory attached to the interior or exterior 

of a motor vehicle in a manner that would make the part 

an attachment to the vehicle or necessary for the operation 

of the vehicle.

NIBRSb Summary UCRa Offense

Appendix Table 2. Continued
 

 Effects of NIBRS on Crime Statistics 15

*Restricted access.

Using NIBRS Data to Analyze Violent Crime, BJS Technical Report, NCJ 144785, 1993

Uniform Crime Reporting State Program Bulletins ------------------------------------- www.leo.gov *

Volume 4: Error Message Manual, 1997 ------------------------------------------- www.fbi.gov/ucr/nibrs/manuals/v4all.pdf

Volume 3: Approaches to Implementing an Incident-Based Reporting System, 1992

Volume 2: Data Submission Specifications, 1997 ----------------------------------- www.fbi.gov/ucr/nibrs/manuals/v2all.pdf

Volume 1: Data Collection Guidelines, 1996 ---------------------------------------- www.fbi.gov/ucr/nibrs/manuals/v1all.pdf

Uniform Crime Reporting, National Incident-Based Reporting System

www.fbi.gov/ucr/nibrs/manuals/nibrsadd.pdf

Uniform Crime Reporting, National Incident-Based Reporting System, 

Addendum to the NIBRS, Vols. 1, 2, 4, 2000 ------------------------------------------

NIBRS Edition, 1992

Uniform Crime Reporting Handbook, 1984

www.ojp.usdoj.gov/bjs/abstract/inibrs.htm

Implementing the National Incident-Based Reporting System: A Project Status Report,

FBI and BJS, 1997 -----------------------------------------------------------------

Crime in the United States, 1998 --------------------------------------------------- www.fbi.gov/ucr/98cius.htm

Conversion of NIBRS to Summary Data, Uniform Crime Reports, 1999 ------------------- www.fbi.gov/ucr/nibrs/manuals/conversion.pdf

http://www.ojp.usdoj.gov/bjs/pub/pdf/v4no1nib.pdf

CJIS Newsletter, 4, 1, NIBRS Edition, 2000 -------------------------------------------- www.leo.gov/lesig/cjis/cjisnews/newsmain.html *

Publications

SEARCH: The National Consortium for Justice Information and Statistics ----------------- www.search.org/nibrs

NIBRS Frequently Asked Questions --------------------------------------------------- www.fbi.gov/ucr/nibrs/faqs.htm

National Archive of Criminal Justice Data ---------------------------------------------- www.icpsr.umich.edu/nacjd

Justice Research and Statistics Association -------------------------------------------- www.jrsainfo.org

Justice Information Center ------------------------------------------------------------ www.ncjrs.org

International Association of Crime Analysts - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - www.iaca.net

FBI Uniform Crime Reports ----------------------------------------------------------- www.fbi.gov/ucr.htm

Crime Mapping Research Center ------------------------------------------------------ www.ojp.usdoj.gov/cmrc

Bureau of Justice Statistics ----------------------------------------------------------- www.ojp.usdoj.gov/bjs

Association of State Uniform Crime Reporting Programs -------------------------------- www.asucrp.org

Related websites

Appendix table 4. NIBRS reference resources

Source: FBI, UCR NIBRS, Volume 4, Error Message Manual, p. 115 (May 1997).

36B-Statutory rape

36A-Incest

240-Motor vehicle theft

23H-All other larceny

23G-Theft of motor vehicle parts

23F-Theft from motor vehicle

23E-Theft from coin machine

23D-Theft from building

23C-Shoplifting

23B-Purse-snatching

23A-Pocket-picking

13C-Intimidation

13B-Simple assault

13A-Aggravated assault

120-Robbery

11D-Forcible fondling

11C-Sexual assault with object

11B-Forcible sodomy

11A-Forcible rape

09B-Negligent manslaughter

09A-Murder

offense. 09A 09B 11A 11B 11C 11D 120 13A 13B 13C 23A 23B 23C 23D 23 23F 23G 23H 240 36A 36B 

09C- Justifiable homicide

cannot occur with any other

Appendix table 3. Excluded combinations of offenses in criminal incidents

Shaded cells denote a combination of offenses which cannot occur to the same victim in an incident.