School Violence

CRIME IN SCHOOLS AND COLLEGES:
A Study of Offenders and Arrestees Reported via
National Incident-Based Reporting System Data

James H. Noonan and Malissa C. Vavra
Crime Analysis, Research and Development Unit
Criminal Justice Information Services Division
Federal Bureau of Investigation
October 2007

Analyses and Results

Incident Characteristics
Of the 17,065,074 incidents reported through the NIBRS by law enforcement from 2000 to 2004, 558,219 (3.3 percent) occurred at schools.  There were 589,534 offense records, 619,453 offenses, and 688,612 offender records reported in those incidents.  The statistics discussed in this report are based on the 476,803 offenders for whom at least one attribute (age, gender, race, and/or number of offenders) was known.¹³  However, none of the characteristics for offenders (age, gender, race, or number of offenders) were known in 211,809 of the 688,612 offender records.  During these 5 years, there were 181,468 arrestees associated with crime in schools.  (See Table 2.)  According to UCR guidelines, the arrestee may be different than the person who was reported as the offender.

Table 2: Overview of Crime in Schools, by Year
	Year of Incident					5-Year Total
	2000	2001	2002	2003	2004
Number of Incidents:						17,065,074
In all locations	2,616,448	3,269,022	3,458,569	3,684,154	4,036,881
In schools	84,627	109,239	110,467	121,765	132,121	558,219
Percent of Incidents in Schools	3.2	3.3	3.2	3.3	3.3	3.3
Characteristics of Incidents in Schools
Number of Offenses	92,242	120,938	123,200	135,489	147,584	619,453
Offense Records	88,687	115,642	117,341	128,542	139,322	589,534
Offender Records1	102,655	134,088	136,358	150,913	164,598	688,612
Unknown Offender Records2	33,239	42,784	41,761	46,106	47,919	211,809
Persons Arrested	24,662	33,280	34,360	41,057	48,109	181,468

¹Includes the number of unknown offender records.
²Unknown offender records are reported when nothing is known about the offenders in the incident, including age, gender, race, and number of offender(s).
See p. 99 of NIBRS Volume 1: Data Collection Guidelines, August 2000, for more

Note: See the study text for specific data definitions, uses, and limitations.

Offender Characteristics
Age was known for 393,938 offenders.¹⁴  Of those, most (38.0 percent) were 13-15 year olds.  The second largest group was 16-18 year olds (30.7 percent), followed by those offenders aged 19 or older (18.2 percent) and 10-12 year olds (11.0 percent).  Offenders 9 years old or under accounted for 2.1 percent of the offenders where the age was known.  By looking at only those offenders for whom the age was known, offenders 18 years of age or younger were 4.5 times more likely to be involved in crime at schools than older offenders.  There were 82,865 offenders for whom the age was unknown (but other characteristics, such as gender and/or race, were known to the police).  (Based on Table 3.)

Table 3: Offenders1 of Crime in Schools, by Age2, by Year
	Year of Incident
Age (Years)	2000	2001	2002	2003	2004	5-Year Total
0–4	35	49	74	53	76	287
5–9	1,246	1,807	1,521	1,563	1,775	7,912
10–12	5,845	8,541	8,859	9,557	10,640	43,442
13–15	20,244	28,171	29,697	33,163	38,347	149,622
16–18	16,732	22,506	23,564	27,533	30,624	120,959
19 or Older	10,748	13,608	14,295	15,637	17,428	71,716
Unknown Age1	14,566	16,622	16,587	17,301	17,789	82,865
Total Offenders3	69,416	91,304	94,597	104,807	116,679	476,803

¹At least one other characteristic (gender, race, or number of offenders) was reported.
²Law enforcement may report a range of ages. NIBRS reports the midpoint of the age range (e.g., offender age 25-35 is reported as 30).
³Over the 5-year study period, there were 211,809 offenders for whom the age, gender, race, and number of offenders were not reported.

Note: See the study text for specific data definitions, uses, and limitations.

For the 5-year study period, the majority (313,556 or 76.7 percent) of the offenders about whom gender was known were males, who were reported as offenders 3.3 times more often than females.  Of the offenders for whom age, race, and/or number of offenders was known, the gender was unknown to law enforcement for 67,796 offenders (14.2 percent).  (Based on Table 4.) 
 

Table 4: Offenders1 of Crime in Schools, by Gender, by Year
	Year of Incident
Gender	2000	2001	2002	2003	2004	5-Year Total
Male	45,011	49	74	53	76	287
Female	12,560	1,807	1,521	1,563	1,775	7,912
Unknown Gender1	11,845	8,541	8,859	9,557	10,640	43,442
Total Offenders2	69,416	91,304	94,597	104,807	116,679	476,803

¹At least one other characteristic (age, race, or number of offenders) was reported.
²Over the 5-year study period, there were 211,809 offenders for whom the age, sex, race, and number of offenders were not reported.

Note: See the study text for specific data definitions, uses, and limitations.

Of the 394,173 offenders about whom race was known, white offenders accounted for 71.1 percent (280,178); black offenders, 27.4 percent (107,878); and all other races combined, less than 2 percent (6,117).¹⁵  When race was known, whites were 2.5 times more likely to be reported as an offender at a school than were all other races combined.  Of the total offenders about whom age and/or gender were known (476,803), race was unknown for 17.3 percent.  (Based on Table 5.)  

Table 5: Offenders1 of Crime in Schools, by Race, by Year
	Year of Incident
Race	2000	2001	2002	2003	2004	5-Year Total
White	41,220	53,862	55,735	61,849	67,512	280,178
Black	13,319	19,876	20,918	24,225	29,540	107,878
Asian/Pacific Islander	584	783	767	936	915	3,985
American Indian/Alaskan Native	282	359	432	433	626	2,132
Unknown Race1	14,011	16,424	16,745	17,364	18,086	82,630
Total Offenders2	69,416	91,304	94,597	104,807	116,679	476,803

¹At least one other characteristic (gender, age, or number of offenders) was reported.
²Over the 5-year study period, there were 211,809 offenders for whom the age, sex, race, and number of offenders were not reported.

Note: See the study text for specific data definitions, uses, and limitations.

Victim-to-Offender Relationships
Table 6 provides breakdowns for victim-to-offender relationships, an important aspect to understand when examining crime at schools.  It is also important to understand the information in Table 6 reflects a count of relationships and not merely the number of victims and/or offenders.  For example, if an incident has four victims and two offenders, there are eight relationship pairings noted in the table (4 victims multiplied by 2 offenders equals 8 relationships).

By far, the relationship type most often reported for crime in schools was Acquaintance, with 107,533 instances occurring during the 5-year study period.  When Acquaintance was combined with the Otherwise Known category (50,486 instances), these two categories were 3.3 times more likely to occur as the relationship than were all other victim-to-offender relationships in which the relationship was known.  The relationship Victim was Offender was reported for 15,539 occurrences, or 7.5 percent of known relationships.  This type of relationship is one in which all participants in the incidents were victims and offenders of the same offense, such as assaults being reported as a result of a brawl or fight.¹⁶  Stranger was reported for 7.5 percent (15,511 instances) of the relationships.  The remaining percentages were widely dispersed among all other relationship categories. 

Table 6: Relationship1 of Victims to Offenders of Crime in Schools, by Year
	Year of Incident
Relationship (victim was . . .)	2000	2001	2002	2003	2004	5-Year Total
Acquaintance	14,074	20,429	22,102	23,647	27,281	107,533
Otherwise Known	6,326	8,960	9,845	11,192	14,163	50,486
Victim was Offender2	1,429	2,805	3,173	3,543	4,589	15,539
Stranger	2,301	3,060	3,045	3,405	3,700	15,511
Friend	1,300	1,465	1,719	1,501	2,006	7,991
Boyfriend/Girlfriend	452	609	600	741	888	3,290
Child	187	220	266	245	326	1,244
Spouse	117	162	155	170	163	767
Other Family Member	117	111	112	131	159	630
Neighbor	110	91	94	116	130	541
Sibling	84	76	102	124	144	530
Parent	66	96	95	79	141	477
Employee	44	76	69	103	146	438
Ex-Spouse	54	67	84	95	78	378
Employer	28	32	43	33	43	179
Babysittee (the baby)	26	23	25	23	26	123
In-Law	10	26	25	27	32	120
Stepchild	12	28	15	22	23	100
Child of Boyfriend/Girlfriend	14	6	14	14	19	67
Stepparent	12	14	15	11	13	65
Homosexual Relationship	2	7	9	16	30	64
Common-Law Spouse	7	18	11	10	16	62
Grandchild	9	7	5	12	15	48
Stepsibling	6	4	10	15	6	41
Grandparent	0	6	5	6	9	26
Relationship Unknown	4,752	7,089	7,184	7,815	8,721	35,561
Total Relationships1	31,539	45,487	48,822	53,096	62,867	241,811

¹There is not a 1:1 correspondence of relationships to incidents. For example, if an incident has 4 victims and 2 offenders, 8 relationship pairings are noted (4 victims multiplied by 2 offenders equals 8 relationships).
²Victim was Offender is a relationship in which all participants in the incidents were victims and offenders of the same offense, such as assaults being reported as a result of a brawl or fight.

Note: See the study text for specific data definitions, uses, and limitations.

Offense Characteristics
A rich level of detail about offense characteristics is captured in the NIBRS format.  Of particular interest for the present study is the month of occurrence/report, use of weapons/force, and suspected use of alcohol, computers, and/or drugs by offenders.¹⁷ 

Table 7 provides the number of incidents as they were reported by month for each year of the study.  The month with the most incidents for the 5-year period was October, with a total of 66,726.  Among the 5-year totals, the month of March had the second-highest number of reported incidents (58,363), and September followed with 57,417 incidents.  It should be noted, however, that on some occasions, the date of the incident is unknown to law enforcement.¹⁸  For example, a school principal notices vandalism at the school on Monday morning and reports the crime.  Though the principal knows the vandalism did not occur before Friday afternoon, neither he nor law enforcement can determine whether it happened Friday evening, Saturday, Sunday, or early Monday morning.  Therefore, law enforcement reports the earliest date in which the incident could have occurred (Friday) as the date of the incident.  In other instances, a crime occurs during a holiday or summer break and is not discovered and reported until the start of school or after the change of a month.  Law enforcement enters the date of the report as the date of the incident, potentially counting the incident in a different month than when it occurred.  In this study, incidents in which the dates of reports were used accounted for 19.5 percent of the incidents reported as having occurred in school locations.  However, the percentages by month for the dates of reports and the actual dates of incidents are very similar (within 0.5 percent for each month), which indicates that only a small percentage of incidents may have occurred in prior months.

Table 7: Incident and Report Date of Crime in Schools by Month, by Year
	Year of Incident
Month	2000	2001	2002	2003	2004	Incident Dates 5-Year Total	Report Dates 5-Year Total
January	6,660	9,275	9,717	10,010	10,610	46,272	9,160
February	8,316	9,781	10,394	10,168	12,808	51,467	9,794
March	9,069	12,056	10,362	12,393	14,483	58,363	11,739
April	7,739	10,520	11,058	12,462	13,038	54,817	10,287
May	8,230	10,920	11,050	12,297	12,337	54,834	10,883
June	4,527	5,187	4,901	5,992	6,019	26,626	5,705
July	3,102	3,880	3,894	4,213	4,245	19,334	4,132
August	4,093	5,167	5,267	5,556	6,063	26,146	4,615
September	8,814	10,539	11,490	12,852	13,722	57,417	10,888
October	10,136	12,919	13,183	15,192	15,296	66,726	12,893
November	8,090	10,553	10,829	11,264	13,178	53,914	10,538
December	5,851	8,442	8,322	9,366	10,322	42,303	7,994
Total Incidents	84,627	109,239	110,467	121,765	132,121	558,219	108,628

Note: Report date counts are included in incident date totals. See the study text for specific data definitions, uses, and limitations.

The particular types of weapons/force used are shown in Table 8.¹⁹  The most common weapon type reported was personal weapons (the offender’s hands, fists, feet, etc.), which were reported 98,394 times.  Personal weapons were 3.4 times more likely to have been reported than any other weapon type (excluding None and Unknown).  The weapon type None was reported 16,260 times in the study, which is relatively large compared to the other known weapon types.  See the table in Appendix B for a cross-table of weapon type by offense type.

Of the 3,461 times guns were reportedly used, handguns were most often reported (58.0 percent).²⁰  Knives/cutting instruments were reportedly used 10,970 times, which outweighs the number of times guns were used by 3.2 to 1.  Law enforcement reported the weapon type Other 11,680 times.²¹  This is quite significant when compared to specific weapon types; however, NIBRS data cannot indicate what types of weapons would fit into this category.  The Other weapon category may contain, for example, acid, pepper spray, belts, deadly diseases, scalding hot water, or other weapon types not covered by the NIBRS weapon type codes.

Table 8: Type of Weapon/Force Used in Crime in Schools, by Year
	Year of Incident
Weapon Type/Force Used	2000	2001	2002	2003	2004	5-Year Total
Personal Weapons	12,945	17,830	20,636	21,933	25,050	98,394
None	2,702	3,114	2,974	3,294	4,176	16,260
Other	1,775	2,311	2,332	2,420	2,842	11,680
Knife/Cutting Instrument	1,511	2,082	2,080	2,445	2,852	10,970
Handgun	307	376	398	430	497	2,008
Blunt Object	283	404	394	455	469	2,005
Firearm (type not stated)	94	131	103	135	146	609
Other Firearm	74	107	92	155	154	582
Explosives	145	139	93	89	95	561
Motor Vehicle	43	52	46	59	71	271
Fire/Incendiary Device	36	34	42	36	88	236
Rifle	23	33	33	24	37	150
Shotgun	15	24	30	19	24	112
Drugs/Narcotics/Sleeping Pills	9	4	8	14	6	41
Poison	1	8	4	11	16	40
Asphyxiation	2	1	3	6	2	14
Unknown	593	1,128	1,163	1,069	1,098	5,051

Note: See the study text for specific data definitions, uses, and limitations.

Table 9 provides the reported instances in each offense record in which the offenders were suspected of using alcohol, computers, and/or drugs.²²   The data show that such use was minimal in situations occurring at schools during the 5-year study period.  Of the 589,534 offense records, reports of offenders suspected of using drugs totaled 32,366, while reports of alcohol use totaled 5,844.  Suspected computer use by offenders was reported for 1,655 instances.  The offender’s suspected use of one or more of these items may have occurred during or shortly before the incident, and the use may have occurred in another location.

Table 9: Reports of Offenders Suspected of Using Alcohol, Computers and/or Drugs in Crime in Schools, by Year
	Year of Incident
Use Category	2000	2001	2002	2003	2004	5-Year Total
Alcohol	998	1,134	1,154	1,212	1,346	5,844
Computer Equipment	376	409	306	256	308	1,655
Drugs/ Narcotics	4,478	6,233	6,146	7,253	8,256	32,366
Not Applicable	83,194	108,315	110,051	120,163	129,745	551,468

Note: See the study text for specific data definitions, uses, and limitations.

Arrestee Characteristics
In addition to the exploration of offenders, it is also important to examine the characteristics of the arrestees associated with crimes in schools.  Though 211,809 offender reports for the 5-year study period were such that age, gender, race, and number of offenders were not reported, some or all of these characteristics were available for 181,468 persons arrested for offenses that occurred at schools.  (See Table 2.)

Table 10 shows the offense for which the arrestee was apprehended.  The most common offense code reported in arrestee records was simple assault–a crime against persons, followed by drug/narcotic violations–a crime against society.  These two arrest offense codes were reportedly associated with more than half (52.2 percent) of the total arrestees.  Destruction/damage/vandalism of property accounted for a relatively small portion of arrestees (6.6 percent).  All other larceny and burglary, both crimes against property, involved 5.8 and 5.0 percent of the arrestees, respectively.  Each of the remaining arrest offense codes accounted for less than 5.0 percent of the arrestees.  Note that the arrest code does not necessarily match any of the offense codes in an offense segment in the same incident.
           

Table 10: Arrestees of Crime in Schools, by Offense, by Year
	Year of Incident
Offense	2000	2001	2002	2003	2004	5-Year Total
Crimes Against Persons:
Simple Assault	6,436	9,136	10,120	11,550	14,220	51,462
Intimidation	830	1,631	1,327	1,434	1,776	6,998
Aggravated Assault	1,009	1,228	1,291	1,427	1,531	6,486
Forcible Fondling	231	300	357	341	446	1,675
Kidnapping/Abduction	43	66	78	80	107	374
Forcible Rape	48	55	31	65	60	259
Sexual Assault With An Object	12	10	34	26	36	118
Forcible Sodomy	19	20	23	20	22	104
Statutory Rape	9	13	11	16	30	79
Murder and Nonnegligent Manslaughter	1	7	7	7	5	27
Incest	0	0	5	2	5	12
Negligent Manslaughter	0	0	0	3	0	3
Crimes Against Property:
Destruction/Damage/Vandalism of Property	1,755	2,141	2,210	2,665	3,138	11,909
All Other Larceny	1,579	2,004	2,004	2,336	2,689	10,612
Burglary/Breaking and Entering	1,430	1,679	1,698	2,130	2,066	9,003
Theft From Building	1,188	1,387	1,440	1,845	1,973	7,833
Stolen Property Offenses	213	256	313	434	476	1,692
Arson	217	234	253	298	356	1,358
Theft From Motor Vehicle	183	205	208	288	274	1,158
Counterfeiting/Forgery	144	210	209	204	207	974
Shoplifting	124	176	165	165	217	847
Motor Vehicle Theft	144	136	182	195	166	823
Robbery	104	144	163	200	191	802
False Pretenses/Swindle/Confidence Game	59	90	155	85	116	505
Impersonation	52	71	120	67	124	434
Theft From Coin-Operated Machine or Device	71	101	80	54	87	393
Theft of Motor Vehicle Parts or Accessories	58	79	56	73	65	331
Credit Card/Automatic Teller Machine Fraud	38	47	42	51	43	221
Embezzlement	29	41	37	62	45	214
Pocket-Picking	33	30	36	33	38	170
Purse-Snatching	18	25	22	38	41	144
Extortion/Blackmail	15	32	22	12	29	110
Wire Fraud	2	2	3	4	8	19
Bad Checks	0	2	4	2	2	10
Bribery	1	1	0	3	3	8
Crimes Against Society:
Drug/Narcotic Violations	5,819	7,860	7,850	9,949	11,816	43,294
Weapon Law Violations	1,219	1,625	1,510	1,872	2,297	8,523
Drug Equipment Violations	717	1,030	967	1,123	1,271	5,108
Disorderly Conduct	194	496	557	751	947	2,945
Trespass of Real Property	79	121	118	192	186	696
Liquor Law Violations	82	123	74	158	157	594
Drunkenness	24	28	50	46	54	202
Pornography/Obscene Material	20	34	49	16	36	155
Driving Under the Influence	9	16	18	27	25	95
Curfew/Loitering/Vagrancy Violations	15	10	25	30	14	94
Betting/Wagering	2	2	13	19	19	55
Prostitution	2	5	4	5	6	22
Operating/Promoting/Assisting Gambling	0	12	0	7	0	19
Gambling Equipment Violations	0	10	2	7	0	19
Family Offenses, Nonviolent	0	0	2	7	9	18
Assisting or Promoting Prostitution	0	0	0	5	1	6
Crimes Against Persons, Property, and Society:
All Other Offenses	358	330	410	621	674	2,393
Non-Crime:
Runaway	27	19	5	7	5	63
Total Persons Arrested		33,280	34,360	41,057	48,109	181,468

Note: See the study text for specific data definitions, uses, and limitations.

The largest group of arrestees about whom the age²³ was known (41.8 percent) was 13 to 15 year olds.  Arrestees who were 16 to 18 years old accounted for 32.7 percent; 19 or older, 14.2 percent; 10 to 12 years old, 10.2 percent; and 5 to 9 years old, 1.1 percent.  Twelve arrestees who committed crimes at schools were reportedly age 4 or under.²⁴  For those arrestees about whom the age was known, arrestees were 6.0 times more likely to be 18 years of age or younger than to be 19 years of age or older.  The age was unknown for 171 of the arrestees.  (Based on Table 11.)

Table 11: Arrestees of Crime in Schools, by Age1, by Year
	Year of Incident
Age (Years)	2000	2001	2002	2003	2004	5-Year Total
0–4	2	3	0	3	4	12
5–9	358	472	410	376	412	2,028
10–12	2,494	3,539	3,607	4,093	4,672	18,405
13–15	10,138	13,960	14,351	17,107	20,266	75,822
16–18	7,863	10,609	10,987	13,726	16,052	59,237
19 or Older	3,770	4,644	4,980	5,726	6,673	25,793
Unknown Age	37	53	25	26	30	171
Total Arrestees	24,662	33,280	34,360	41,057	48,109	181,468

¹Law enforcement may report a range of ages. NIBRS reports the midpoint of the age range (e.g., offender age 25-35 is reported as 30).
Note: See the study text for specific data definitions, uses, and limitations.

During the 5-year period, 78.2 percent of the 181,468 arrestees were males, who were 3.6 times more likely to be arrested than females.  (Based on Table 12.)

Table 12: Arrestees of Crime in Schools, by Gender, by Year
	Year of Incident
Gender	2000	2001	2002	2003	2004	5-Year Total
Male	19,717	26,343	26,812	32,146	36,868	141,886
Female	4,945	6,937	7,548	8,911	11,241	39,582
Total Arrestees	24,662	33,280	34,360	41,057	48,109	181,468

Note: See the study text for specific data definitions, uses, and limitations.

Of the 179,109 arrestees about whom the race was known, 72.8 percent were white; 25.3 percent were black; and 1.9 percent were all other race categories combined.  White was 2.7 times more likely to be reported as the arrestee race than were any of the other race categories.  A total of 2,359 arrestees were reported with an unknown race.  (Based on Table 13.)

Table 13: Arrestees of Crime in Schools, by Race, by Year
	Year of Incident
Race	2000	2001	2002	2003	2004	5-Year Total
White	18,589	24,194	24,943	29,084	33,518	130,328
Black	5,308	8,032	8,274	10,663	13,077	45,354
Asian/Pacific Islander	277	410	383	523	521	2,114
American Indian/Alaskan Native	171	232	289	268	353	1,313
Unknown Race	317	412	471	519	640	2,359
Total Arrestees	24,662	33,280	34,360	41,057	48,109	181,468

Note: See the study text for specific data definitions, uses, and limitations.

Law enforcement agencies submitting NIBRS data are not required to report the ethnicity of the arrestee to the FBI.  Of the 136,957 arrestees about whom ethnicity was known and reported, 89.4 percent were non-Hispanic.  Excluding unknown ethnicity, arrestees were 8.4 times more likely to be non-Hispanic.  (Based on Table 14.)  There were 18,208 arrestees about whom the ethnicity status was not reported during the 5-year study period.    

Table 14: Arrestees1 of Crime in Schools, by Ethnicity, by Year
	Year of Incident
Ethnicity	2000	2001	2002	2003	2004	5-Year Total
Hispanic	1,729	2,439	2,862	3,439	4,103	14,572
Non-Hispanic	16,791	22,783	23,631	27,638	31,542	122,385
Unknown Ethnicity	3,793	4,440	4,631	5,820	7,619	26,303
Total Arrestees1	22,313	29,662	31,124	36,897	43,264	163,260

¹Over the 5-year study period, there were 18,208 arrestees for whom the ethnicity was not reported.
Note: See the study text for specific data definitions, uses, and limitations.

As with supplying the ethnicity of an arrestee, providing resident status for an arrestee is an optional reporting field in the NIBRS.  For the purpose of this study, a resident is a person who maintains his/her permanent home for legal purposes in the locality (that is, town, city, or community) where the school is located and in which the crime occurred.²⁵  Of the 145,339 arrestees about whom resident status was known and reported, 79.2 percent were residents.  When the resident status was known, arrestees were nearly
3.8 times more likely to be residents of the community in which the crime took place.  (Based on Table 15.)  During the 5 years of data submissions from 2000 to 2004, there were 17,767 arrestees about whom resident status was not reported to the UCR Program. 

Table 15: Arrestees1 of Crime in Schools, by Resident Status, by Year
	Year of Incident
Resident Status	2000	2001	2002	2003	2004	5-Year Total
Resident2	15,367	20,661	21,609	26,294	31,112	115,043
Nonresident	4,278	5,686	5,768	6,811	7,753	30,296
Unknown Residence	2,263	3,155	3,193	4,294	5,457	18,362
Total Arrestees1	21,908	29,502	30,570	37,399	44,322	163,701

¹Over the 5-year study period, there were 17,767 arrestees for whom the resident status was not reported.
²A resident is a person who maintains his/her permanent home for legal purposes in the locality (i.e., town, city, or community) where the crime took place.
Note: See the study text for specific data definitions, uses, and limitations.

Limitations
Studies that use NIBRS data have inherent limitations.  First, when the NIBRS data show increases in crime over a period of years, it should not be assumed that the volume of criminal incidents in the Nation actually increased.  As seen in Table 1, such apparent increases from year to year may well be the result of increases in the number of law enforcement agencies (1,934 more agencies over the 5-year period) reporting their UCR data via the NIBRS format.  As the percentage of agencies participating in the UCR Program via the NIBRS increases and the NIBRS data become more representative of crime nationwide, data analysts will be better equipped to identify increases and decreases in crime that are due to actual changes in crime volume rather than to reporting.  Furthermore, changes in proportions between groups should not be interpreted as an actual change in the Nation’s crime characteristics.  It is possible that demographics of the new reporting agencies are influencing the proportion (e.g., should the data show a sharp increase in the percentage of one particular race of offender between two years).  As more law enforcement agencies report via the NIBRS, analysts will be more confident that the demographic characteristics of the data can be considered nationally representative.  It is expected that, eventually, the NIBRS data, combined with other exogenous datasets, will allow researchers to evaluate the effect of crime reduction policies in reducing crime.  Another potential limitation is that the agencies that submit their UCR data via the NIBRS format are not, for the most part, in large metropolitan areas.  In spite of these limitations, there have been studies that suggest that the NIBRS data may be representative of the Nation’s crime (see, for example, Section V of Crime in the United States, 2002, “Bank Robbery in the United States”). 

Another limitation of studies that use NIBRS data stems from the restricting level of disaggregation possible when using NIBRS location codes.  For example, crimes committed at school, college, and university locations are all combined into a single NIBRS location code.  Separating elementary and secondary schools from colleges is difficult, if not impossible, in the NIBRS format.  The parameters available in NIBRS that might help distinguish whether an incident took place at an elementary school, secondary school, or college are not mutually exclusive to any group.  For example, there are many 17 year olds in college and, conversely, many 18 year olds in high school during the same period of time; therefore, age of victim, offender, or arrestee are not variables that can identify whether the incident occurred in an elementary school, secondary school, or college.  In addition, neither the victim nor the offender necessarily attends the institution where the offense occurred.

Lastly, the validity of NIBRS data has not been tested; therefore, one should be cautious in the interpretation of surprising findings, e.g., twelve 0-4 year old arrestees.  (See Table 11.)  However, since one purpose of this study is to show the arrestee and offender information that can be gleaned from incidents involving crime in school locations reported via the NIBRS, data such as these are included in the study.

Because of these limitations, the findings discussed in the present study cannot be generalized to the Nation as a whole.  Readers are advised to be cautious in applying the results of this study to other research.

School Violence Index