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U.S. Department of Justice

Office of Justice Programs

Office of Juvenile Justice and Delinquency Prevention 

August 2008

National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children

Office of Justice Programs

Partnerships for Safer Communities

www.ojp.usdoj.gov

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U.S. Departaof Justice

Office of Justice Programs

Office of Juvenile Justice and Delinquency Prevention 

National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children

J. Robert Flores

OJJDP Administrator

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U.S. Department of Justice

Office of Justice Programs

Office of Juvenile Justice and Delinquency Prevention 

National Incidence Studies of Missing, Abducted, Runaway, and Thrownaway Children

Office of Justice Programs

Innovation • Partnerships • Safer Neighborhoods

www.ojp.usdoj.gov

Access OJJDP publications online at www.ojp.usdoj.gov/ojjdp

Sexually Assaulted Children:

National Estimates and

Characteristics

David Finkelhor, Heather Hammer, and 

Andrea J. Sedlak

This series of Bulletins summarizes findings from the Second

National Incidence Studies of Missing, Abducted, Runaway, and

Thrownaway Children (NISMART–2). The main purpose of the series

is to provide a clear picture of how many children become missing—

and why. Bulletins in the series offer national estimates of missing

children based on surveys of households, juvenile residential facilities, and law enforcement agencies. The Bulletins also present

statistical profiles of these children, including their demographic

characteristics and the circumstances of their disappearance. In

addition, the series offers analyses of selected special topics, based

on NISMART–2 data.

This Bulletin, the seventh in the NISMART–2 series, addresses a

special topic: sexually assaulted children. The Bulletin provides

information on the estimated number and characteristics of children who were sexually assaulted in the United States in 1999,

based on NISMART–2 interviews with victims and their families.

The estimates are derived from two components of the Second

National Incidence Studies of Missing, Abducted, Runaway, and

J. Robert Flores, Administrator
NISMART 

Thrownaway Children (NISMART–2): the National 

Household Survey of Adult Caretakers and the National 

Household Survey of Youth. These surveys were conducted during 1999 and reflect a 12-month period. 

Because the vast majority of cases reported were concentrated in 1999, the annual period referred to in the 

Bulletin is 1999. 

Key Findings 

■	 In 1999, an estimated 285,400 children were victims 

of a sexual assault1 and 35,000 were victims of some 

other type of sex offense. 

■	 An estimated 44 percent of the child victims of sexual 

assault and other sex offenses experienced an act of 

sexual penetration. 

■	 Sexual assault victims were disproportionately female 

(89 percent) and ages 12 to 17 (81 percent). 

■	 Most (95 percent) of the sexual assault victims were 

assaulted by a male. Almost three-fourths (71 percent) 

were assaulted by someone they were acquainted 

with or knew by sight; 18 percent were assaulted by 

a complete stranger, 10 percent by a family member. 

■	 Twenty-nine percent of the sexual assault victims 

were assaulted by youth age 17 or younger. 

■	 Police were contacted in regard to only 30 percent 

of the sexually assaulted children. 

Background: Availability of Data on 

Sexually Assaulted Children 

Sexual assaults against children are among the most 

highly publicized serious crimes. However, accurate and 

complete national estimates of their incidence have not 

been readily available. 

The nation’s most widely used crime statistics, the Federal Bureau of Investigation’s annual report on crimes 

reported to police (FBI, 2001), do not differentiate sexual 

assaults against juveniles from those against adults, so 

this frequently cited source cannot be used to count 

juvenile victims of sexual assault. However, a reanalysis 

of the FBI’s National Incident-Based Reporting System 

(NIBRS) data from 12 states for 1991–96 indicates that in 

one-third of all sexual assaults reported to law enforcement, the victim was younger than age 12 (Snyder and 

Sickmund, 1999:29). 

The National Child Abuse and Neglect Data System 

(NCANDS), which is based on reports from child protective agencies in participating states, provides annual 

counts of incidents of child sexual abuse. However, 

NCANDS is far from comprehensive because the agencies providing these reports investigate offenses committed primarily by caretakers (U.S. Department of Health 

and Human Services, 2001). Thus, NCANDS excludes a 

substantial number of the sex offenses against juveniles, 

especially those committed by nonfamily members. 

NIBRS and NCANDS share another important limitation as sources of information about sexually assaulted 

children. These official sources have been found to 

underrepresent the incidence of sexual assault because 

victims tend to underreport these events to law enforcement and other agencies (Finkelhor, 1994). 

The National Crime Victimization Survey (NCVS), 

which interviews victims who did not report the crime 

to police in addition to those who did, provides information that is not available from police data (U.S. Department of Justice, 2000). However, NCVS underestimates 

the incidence of sexual assaults against children because 

it does not collect reports on crimes against children 

younger than 12—an important age group for estimates 

of sexual assault. 

Because of these limitations, many of the most frequently cited estimates about child sexual assault have 

come from adult retrospective surveys (Bolen, 2001). 

These studies have other limitations. For example, it 

has generally been found that crime victimization recall 

deteriorates over time (Skogan, 1986). Moreover, adult 

retrospective reports cannot readily provide single-year 

incidence rates, which are the usual format in which 

crime victimization statistics are displayed. In addition, 

adult retrospective statistics reflect the experience of the 

previous, not the current, generation and do not easily 

allow for the measurement of trends. 

Because Congress found that many missing children are 

at risk of sexual exploitation (42 U.S.C. 5771 Sec. 402) 

and because sexual assault is often the motive for nonfamily abduction, NISMART–2 included screening 

2 
NISMART 

questions and interview sections designed to allow 

counts of sexual assaults. This Bulletin reports the 

sexual assault findings. 

Methodology 

The sexual assault estimates in this Bulletin are based 

on a nationally representative sample of children. The 

information on victimizations for this sample was 

obtained through proxy interviews with caretakers (for 

NISMART–2 Definitions 

Rape and Sexual Assault 

Rape 

Rape is forced sexual intercourse, meaning vaginal, 

anal, or oral penetration, including penetration by a 

foreign object and oral sex, where “force” includes 

both psychological coercion (threat) as well as physical 

force. Forced penetration occurs if the offender penetrates the victim or the victim is forced to penetrate 

the offender (as would be the case when the offender 

performs oral sex on a male victim). Additionally, 

NISMART–2 counts any situation where respondents 

described the situation with the term rape, and actual 

penetration (including oral sex) was reported in the 

subsequent questions that asked about penetration. 

Attempted Rape 

An attempted rape is an incident in which the perpetrator intends to force the victim to have sexual intercourse or oral sex, including verbal threats of rape, but 

the perpetrator does not penetrate the victim or successfully engage in oral sex. 

NISMART–2 counts an incident as an attempted rape if 

there is any mention of the term “attempted rape” or 

“tried to [sex act that would involve penetration, like 

‘make me suck him’]” or any “tried to,” “attempted,” 

or “make me” expression that strongly implies intercourse, like “make me sleep with him.” Additionally, 

NISMART–2 counts any situation where respondents 

described the situation with the term rape, but actual 

penetration (including oral sex) was not reported in the 

subsequent questions that asked about penetration. 

Sexual Assault 

Sexual assault is separate from rape or attempted rape 

and is a mutually exclusive category. Sexual assaults 

involve unwanted sexual contact and must include the 

use or attempted use of force or threat. Unwanted sexual contact occurs when the perpetrator touches the 

child’s private parts (defined as breasts, genitals, and 

buttocks) on skin or on top of clothes or when the child 

is forced or coerced to touch the perpetrator’s private 

children ages 0–17) and through interviews with the 

victims themselves (for children ages 10–17), conducted 

in 1999 as part of the NISMART–2 National Household 

Surveys of Adult Caretakers and Youth. The surveys 

used computer-assisted telephone interviewing methodology to collect information from a national probability 

sample of households. 

Interviews were completed with 16,111 adult primary caretakers. The total number of children in the 

parts on skin or on top of clothes. Any mention of
 

unwanted touching, under or over clothing, of private
 

parts counts as unwanted sexual contact in NISMART–
 

2. “Unwanted” is to be broadly determined from the
 

context of the respondent’s remarks, including signs of
 

being upset about the episode or agreement with any
 

of the negative question items (e.g., “unwanted sex” or
 

“attempted assault”) in regard to it. 


Attempted Sexual Assault 

An attempted sexual assault is an unsuccessful attempt
 

at unwanted sexual contact that is not an attempted
 

rape and does not actually involve any unwanted sexual contact. An attempted sexual assault can occur only
 

with the use or attempted use of force or threat. An
 

attempted sexual assault includes any mention of the
 

term “attempted or tried to” in conjunction with any
 

sexual assault, molestation, or sexual abuse that is not
 

classified as an attempted rape. If any touching of sexual areas actually occurs, then the incident is an actual
 

rather than attempted sexual assault. 


Related Definitions 

Force, Attempted Force, or Threat of Force 

Any action of grabbing, pushing, restraining, hitting,
 

kicking, chasing, surrounding, knocking down, tripping,
 

holding, throwing objects, or displaying a weapon is
 

considered as using force in the context of a sex-related
 

crime. These definitions include the use of physical
 

force to dislodge or remove the victim’s clothing. Any
 

attempt to engage in these actions or any threat of
 

engaging in these actions is considered as attempted
 

force or threat of force and is sufficient to classify an
 

incident as involving force.
 

Noncontact Sex-Related Crimes 

Noncontact sex-related crimes include incidents of
 

voyeurism and exhibitionism that are not already classified as rapes, attempted rapes, sexual assaults, or
 

attempted sexual assaults. Voyeurism is the unwanted
 

viewing of the child’s private parts. Exhibitionism is the
 

unwanted and intentional display of the offender’s private parts to the child.
 

3 
NISMART 

households of respondents in the Household Survey sample was 31,787. Each primary caretaker who completed 

an interview was asked for permission to interview one 

randomly selected youth in the household between the 

NISMART–2 Household Survey 

of Adult Caretakers: Child 

Sexual Assault Episode 

Screening Questions 

Questions 13–16 initiate a sexual assault followup
 

interview.
 

(13) Was there any time when anyone tried to sexually 

molest, rape, attack, or beat up [this child/any of these 

children]? 

(14) In the past 12 months, has anyone attacked or 

threatened [this child/any of these children] in any of 

these ways: 

■ With any weapon, for instance, a gun or knife; 

■	 With anything like a baseball bat, frying pan,
 

scissors, or stick;
 

■ By something thrown, such as a rock or bottle; 

■ Including any grabbing, punching, or choking; 

■	 Any rape, attempted rape, or other type of
 

sexual attack;
 

■ Any face-to-face threats; 

■	 Any attack or threat or use of force by anyone
 

at all?
 

Something that happens to some children these days is 

that adults or other youth try to force or trick them into 

doing something sexual. This includes trying to touch 

the child’s private parts or trying to make the child 

touch or look at the other person’s private parts. Children report that these kinds of things happen with people they know well or trust, like teachers or relatives. 

(15) In the past 12 months, has there been a time when 

an older person, like an adult, an older teenager, or a 

babysitter, deliberately touched or tried to touch your 

child’s private parts or tried to make your child touch 

or look at their private parts, when your child didn’t 

want it? 

(16) [Has/have] [this child/any of these children] been 

forced or coerced to engage in unwanted sexual activity 

by someone [he/she/they] didn’t know before, a casual 

acquaintance, or someone [he knows/she knows/they 

know] well? 

ages of 10 and 18. Permission was obtained for 60 percent 

of the selected youth, yielding 5,015 youth interviews.2 

The NISMART–2 Household Surveys were designed to 

screen for sexual assaults that met the study definitions 

(see sidebar on page 3). Adult caretakers were asked four 

screening questions (see sidebar on this page); the screening questions asked of youth were essentially the same. 

If the answer to any of the questions was “yes,” the 

following specific questions were asked to confirm 

the episode. 

During this episode, was the child sexually abused 

or molested? 

During this episode, was there an attempt to sexually 

abuse or molest the child? 

Then, if the episode was confirmed, the following 

questions were asked to collect the detailed information used to categorize the type of sexual assault: 

Did the perpetrator touch the child’s private parts in 

any way? 

Did the perpetrator get the child to touch his/her private parts in any way? 

Did the perpetrator actually put some part of his/her 

body or something else inside of the child? 

Did the perpetrator try to put some part of his/her 

body or something else inside of the child? 

Did the perpetrator actually put his/her mouth on the 

child’s private parts, or get the child to put his/her 

mouth on the perpetrator’s private parts?3 

Youth and adults in the same household could potentially disclose the same episode; when this happened, 

the child was counted only once. Children who were 

sexually victimized on different occasions because of 

multiple episodes, including different victimizations 

disclosed by the youth and caretaker, were counted 

only once. In developing national estimates of sexually 

assaulted children, data from both the youth and adult 

interviews were weighted to reflect the Census-based 

population of children. For additional methodological 

details, see OJJDP’s NISMART–2 Household Survey 

Methodology Technical Report (Hammer and Barr, 

forthcoming). 

4 
NISMART 

Results 

An estimated 285,400 children ages 17 and younger 

experienced a sexual assault in 1999 (table 1), a rate of 

about 4.1 victims per 1,000 children in the U.S. population. Of these, 141,400 children experienced a rape 

(defined in the study as anal, oral, or vaginal penetration). An additional 60,400 experienced an attempted 

rape, and 55,900 were victims of a sexual assault that 

did not involve penetration. Another 27,600 experienced 

an attempted sexual assault (i.e., the perpetrator did not 

actually touch the child’s sexual areas). Together, these 

four categories total an estimated 285,400 children who 

were victims of actual and attempted rapes and other 

actual and attempted sexual assaults, referred to collectively as “sexual assaults” in the analysis that follows. 

An additional 35,000 children who were victims of 

other sex offenses not typically defined as sexual 

assaults (primarily acts of exhibitionism or voyeurism 

without actual physical contact or force) have been 

excluded from the tables that follow because the numbers in this category were too small to analyze separately 

with any degree of reliability. 

Characteristics of Victims 

Females constituted the vast majority (89 percent) of 

sexual assault victims (table 2). Juveniles ages 12–17 

made up 81 percent of the victims; older teenagers (ages 

15–17) were disproportionately represented (54 percent 

of all victims compared with 17 percent of the general 

child population). Victimization of whites and blacks 

was proportionate to their percentages in the general 

child population. Hispanics constituted 9 percent of victims, compared with 16 percent of the child population. 

Characteristics of Perpetrators 

Twenty-three percent of the victims were assaulted by 

more than one perpetrator; these assaults were classified 

according to the characteristics of the perpetrator most 

closely related to the victim (table 3). 

Ten percent of all victims were assaulted by a family 

member, including 4 percent who were assaulted by 

their father and 5 percent by a brother or other relative. 

Most of the children (64 percent) were assaulted by an 

acquaintance, including 4 percent who were assaulted by 

an authority figure or a caretaker. Twenty-five percent of 

the victims were assaulted by a stranger, including someone the child knew by sight but not on a personal basis. 

For 29 percent of victims, the assailant was age 17 or 

younger, including a small number of assailants younger 

than age 12. Forty-four percent of victims were assaulted 

by an adult younger than age 30, and about a fifth by 

someone 30 or older. The vast majority (95 percent) of 

the victims were assaulted by a male. 

Characteristics of Assaults 

Fourteen percent of the victims were assaulted in their 

own home and another 38 percent were assaulted in 

someone else’s home (table 4). Almost a fourth (23 percent) of the victims were assaulted in a public area. 

Cars and vehicles were the assault site for 9 percent of 

the victims, work locations for 6 percent. Victims for 

whom information on assault duration was available 

were about equally divided between incidents lasting 

less than an hour and incidents lasting an hour or longer. 

Ten percent of the victims were assaulted by someone 

using a weapon. For 23 percent of victims, the sexual 

assault took place during the course of a nonfamily or 

family abduction.4 Seventeen percent of victims were 

injured. 

For 31 percent of the victims, the assault occurred in the 

summer. Children were more likely to be victimized 

on Friday or Saturday compared to other days and least 

likely to be victimized in the morning compared to the 

afternoon, evening, or night. 

Police Contacts 

Police were contacted about the sexual assault for only 

30 percent of the victims (table 5). The most common 

reason for not contacting the police was that the victimized youth did not want the caretakers to find out about 

the episode because of circumstances they probably 

would have disapproved of, such as the youth’s being 

under the influence of drugs or alcohol at the time of 

the assault. 

5 
NISMART 

Notes: Estimates are rounded to the nearest 100 and may not sum to the total. Percents may not sum to 100 because of rounding. Gender, age, and race distributions for the U.S. population were based on the average monthly estimates of the population ages 0–17 for 1999 (U.S. Census Bureau, 2000). 

*Estimate is based on too few sample cases to be reliable. Another study with the same sample size and methodology might produce a very different estimate. 

Table 1: Estimates of Sexual Offenses Against Children 

95% Confidence 

Type of Incident Estimate Interval Percent 

Rape 141,400 71,800–211,000 44 

Attempted rape 60,400* 13,400–107,400 19* 

Other sexual assault 55,900 <100–133,100 17 

Attempted other sexual assault 27,600* 3,300–51,900 9* 

All rape and other sexual assault 285,400 200,400–370,300 89 

Other sex offense 35,000 10,200–59,800 11 

All rape, other sexual assault, 320,400 231,900–408,900 100 

and other sex offense 

Notes: For definitions of types of incidents, see page 3. Estimates are rounded to the nearest 100 and may not sum to the total. 


*Estimate is based on too few sample cases to be reliable. Another study with the same sample size and methodology might produce a very different estimate.
 

Table 2: Characteristics of Sexually Assaulted Children 

Sexual Assault Victims 

(n = 285,400) Percent of U.S. Child Population 

Characteristic of Child Estimate Percent (N = 70,172,700) 

Gender 

Female 252,700 89 49 

Male 32,700 11 51 

Age (years) 

0–5 12,300* 4* 33 

6–8 9,800* 3* 17 

9–11 30,500 11 17 

12–14 77,900 27 17 

15–17 154,800 54 17 

Race/ethnicity 

White, non-Hispanic 182,000 64 63 

Black, non-Hispanic 52,200 18 16 

Hispanic 26,500* 9* 16 

Other 23,500* 8* 6 

No information 1,200* <1* — 

6 
NISMART 

Table 3: Characteristics of Sexual Assault Perpetrators 

All Sexual Assault Victims 

Characteristic of (n = 285,400) 

Perpetrator Estimate Percent 

More than one perpetrator 

Yes 64,800 23 

No 216,500 76 

No information 4,000* 1* 

Identity of main perpetrator 

Family member 27,200 10 

Father 12,600* 4* 

Brother 5,700* 2* 

Other relative 9,000* 3* 

Acquaintance 183,200 64 

Child’s friend or acquaintance 148,100 52 

Family friend or acquaintance† 23,300* 8* 

Authority or caretaker 11,800* 4* 

Stranger 72,400 25 

Known only by sight 20,200* 7* 

Complete stranger 52,200 18 

No information 2,500* 1* 

Main perpetrator’s age 

12 or younger 12,000* 4* 

13–17 71,700 25 

18–29 124,700 44 

30–39 23,100* 8* 

40–49 21,600* 8* 

50+ 8,100* 3* 

No information 24,100* 8* 

Main perpetrator’s gender 

Male 272,500 95 

Female 10,300* 4* 

No information 2,500* <1* 

Table 4: Characteristics of Child Sexual 

Assaults 

Percent of All Sexual 

Characteristic of Assault Victims 

Episode (n = 285,400) 

Location 

Own home 14 

Other home 38 

Car or other vehicle 9 

Work 6* 

Public area 23* 

Other location 8* 

Duration 

Less than 1 hour 42 

1 hour or longer 46 

No information 12 

Coercive elements and harm 

Perpetrator used weapon 10* 

Child was abducted 23 

Child was injured 17 

Season 

Winter 21 

Spring 28 

Summer 31 

Fall 20 

Day of week 

Monday through Thursday 12 

Friday 36 

Saturday 17* 

Sunday 4* 

No information 31 

Time of day 

Morning 2* 

Afternoon 27 

Evening 30 

Night 32 

No information 9* 

Notes: Estimates are rounded to the nearest 100 and may not sum to the total. Percents 

may not sum to 100 because of rounding. 

*Estimate is based on too few sample cases to be reliable. Another study with the same 

sample size and methodology might produce a very different estimate. 

†Includes neighbors. 

Note: Percents may not sum to 100 because of rounding. 

*Estimate is based on too few sample cases to be reliable. 

Another study with the same sample size and methodology 

might produce a very different estimate. 

7 
NISMART 

Note: For the responses on why police were not contacted, percents are 

computed from a baseline of 198,600—the number of children with no 

police contact. 

*Estimate is based on too few sample cases to be reliable. Another study 

with the same sample size and methodology might produce a very different estimate. 

Table 5: Police Contact for Child Sexual Assaults 

Percent of All Sexual 

Police Contact for Assault Victims 

Episode (n = 285,400) 

Any police contact 

Yes 30 

No 70 

Why police were not contacted 

Child did not want caretaker 

to find out about assault or 

caretaker was told too long 

after assault occurred 59 

Not serious enough 9* 

Child wanted to protect 

perpetrator 4* 

Other reason 23 

No information 5* 

Implications 

Comparisons to Other Data Sources 

To obtain a more comprehensive estimate of the incidence of child sexual assault than was previously available, this study used national samples of caretakers and 

NCVS Sexual Assault 

Definitions 

Rape 

Rape is forced sexual intercourse, which includes both 

psychological coercion as well as physical force. Forced 

sexual intercourse means vaginal, anal, or oral penetration by the offender(s). This category also includes incidents where the penetration is from a foreign object 

such as a bottle. 

Attempted Rape 

An attempted rape is an incident in which the perpetrator intends or attempts to force the victim to have sexual intercourse, including verbal threats of rape, but 

does not succeed in having sexual intercourse with 

the victim. 

youth to gather information about the victimization 

experiences of children of all ages. As a result, the 

NISMART–2 estimate of 285,400 children sexually 

assaulted in 1999 is significantly higher than estimates 

available from other sources. Two major sources mentioned earlier in this Bulletin produced counts or estimates of 82,000 (NCANDS) and 72,300 (NCVS) for 1999. 

As mentioned previously, NCANDS, a frequently used 

source of statistics on sexual assaults against children, is 

based on reports from child protective agencies. Because 

it excludes most sex crimes against children committed 

by noncaretakers, and because it includes only cases 

reported and substantiated by child protection authorities, NCANDS is not comprehensive and, not surprisingly, produced a count much lower than the 

NISMART–2 estimate. 

The NCVS estimates, which are based on interviews 

with victims, are also substantially lower than the 

NISMART–2 estimates. Differences in definition are 

unlikely to account for this discrepancy, because the 

researchers made a conscientious effort to align 

NISMART–2 definitions with NCVS definitions (see 

sidebars on pp. 3 and 8). 

Two major differences in methodology, however, likely 

contributed significantly to the discrepancy in estimates. 

First, NCVS obtains victimization information from 

direct interviews with persons age 12 and older, whereas 

Sexual Assault 

Sexual assault includes a wide range of victimizations, 

separate from rape or attempted rape. These crimes 

include attacks or attempted attacks generally involving 

(unwanted) sexual contact between victim and offender. 

Sexual assaults may or may not involve force, such as 

grabbing or fondling, and may also include verbal 

threats. 

Attempted Sexual Assault 

An attempted sexual assault is an unsuccessful attempt 

at unwanted sexual contact, including verbal threat of 

sexual assault, that is not an attempted rape and does 

not involve any actual unwanted sexual contact. 

Source: U.S. Bureau of Justice Statistics, National Crime Victimization Survey, 1992–1998 Codebook for Parts 53–56, Washington, DC: U.S. Department of Justice, Office of Justice Programs, Bureau of Justice Statistics, 

2000. 

8 
NISMART 

NISMART–2 interviewed children as young as 10. Second, 

in addition to information collected directly from the 

sample of youth age 10 or older, NISMART–2 also collected proxy information from caretakers for children of 

all ages. Thus, NISMART–2 counted two kinds of sexual 

assault episodes that NCVS methodology excludes: (1) 

assaults of children younger than 12; and (2) assaults of 

children age 12 or older who did not disclose the incident 

themselves but whose caretaker knew of and disclosed 

the incident. Both of these factors would make the 

NISMART–2 estimates higher than the NCVS estimates. 

Additional methodological differences between 

NISMART–2 and NCVS cannot be specifically quantified but may have influenced the discrepancy between 

the two sets of estimates. First, NISMART–2 used a 

single interview to ask about a 1-year time period, 

whereas NCVS interviews participants every 6 months 

over a 3-year period (and so is better able to assure that 

assaults that occurred outside a 1-year estimating period 

have not been mistakenly telescoped into the estimate). 

Second, some NCVS interviews are conducted in person, 

whereas NISMART–2 conducted all interviews by telephone. Third, the NCVS survey has a very explicit crime 

focus, which may inhibit reports about events (such as 

sexual assaults by acquaintances and other youth) that 

respondents may not conceptualize as crimes.5 Finally, 

although the NCVS and NISMART-2 definitions of rape, 

attempted rape, sexual assault, and attempted sexual 

assault are similar, the interviews use different questions 

to determine if an episode qualifies. All of these factors 

may account for lower numbers in the NCVS estimates. 

To examine the discrepancy between NISMART–2 and 

NCVS controlling for as many methodological differences as possible, the number of NISMART–2 children 

who were sexually assaulted was re-estimated using 

only, as in NCVS, the self-reports of youth ages 12–17 

at the time of the assault.6 This comparison between 

the NISMART–2 and NCVS sexual assault estimates for 

1999, based entirely on self-reports from youth ages 

12–17, finds that the NISMART–2 estimate of sexually 

assaulted children is still at least three times greater 

than the NCVS estimate: 219,700 vs. 72,300.7 

The difference between NISMART–2 and NCVS estimates 

might be even greater if another important methodological 

difference could be taken into consideration. NISMART–2 

counted children with multiple sexual assaults only once, 

whereas NCVS counts each episode. Thus, the NISMART–2 

estimate could potentially be even higher had the survey 

counted assaults rather than victims. 

Indications of Underreporting 

Even though NISMART–2 produced higher estimates than 

other data sources, many indications of underreporting 

suggest that the NISMART–2 estimates are undercounts. 

For example, more than half of the youth who were interviewed after their caretaker disclosed the youth’s victimization did not disclose the assault in their own interview. 

As a result, one would expect that a considerable number 

of additional youth whose caretakers did not know about 

the assault also failed to disclose. Additionally, the accuracy of the proxy reports by caretakers could be influenced 

by their not wanting to disclose the abuse to a telephone 

interviewer. The latter situation would have a proportionally larger effect on underreporting for victims younger 

than 10, for whom caretaker proxy reports were the only 

source of information. 

For these reasons, the distribution of sexual assaults in 

this sample is skewed in comparison to the distributions 

obtained from many adult retrospective surveys (Finkelhor and Baron, 1986). The sample contains proportionately fewer assaults by family members and against 

younger children than usually appear in such retrospective surveys. Because of ongoing intimidation and family 

loyalty, children typically find it difficult to disclose 

family abuse. Younger children are especially reluctant 

to disclose family abuse and, as noted above, the experience of children younger than 10 could only be represented in the NISMART–2 survey if their caretaker knew 

about it and disclosed it. Thus, younger children who 

have been sexually abused by family members are the 

type of abuse victim most likely to be underreported in 

NISMART–2. 

Methodological Innovations 

It may be inherently impossible to get a complete and 

unbiased accounting of all child sexual assaults close to 

the time they occur. Nevertheless, the current study 

suggests that a much clearer picture of the problem’s full 

dimension can be revealed by including caretakers as 

9 
NISMART 

proxy reporters and by trying to assess victimization 

across the whole age range of childhood. Table 6 disaggregates the NISMART–2 estimate of sexually assaulted 

children by source of information (self-reports for children ages 12–17 and 10–11, proxy reports for children 

ages 12–17 and younger than 12). Proxy reports accounted 

for 34 percent of the estimate (18 percent for children 

ages 12–17 and 16 percent for children younger than 12). 

Reports concerning children younger than 12 comprised 

18 percent of the estimate; most of these reports were 

from caretakers, but 2 percent were from self-reports of 

children age 10 or 11. 

Using proxy interviews to obtain information on crime 

victimization and other sensitive topics has never been 

a preferred methodology and has sometimes yielded poor 

results. However, the method certainly merits further 

investigation as a means of studying sexual assaults of 

younger children, given the seriousness of these incidents, the importance of getting good epidemiological 

information about them, and the likelihood that caretakers are most aware of their children’s experiences 

when the children are young. A recent comparison of 

proxy and self-reports of victimization among preadolescent children yielded evidence that such a mixed 

approach can be useful (Finkelhor et al., 2005). 

In addition to these methodological innovations, 

NISMART–2 added two new screening questions to 

those that NCVS uses: 

Was there any time when anyone 

tried to sexually molest, rape, attack, 

or beat up [this child/any of these 

children]? 

In the past 12 months, has there been 

a time when an older person, like an 

adult, an older teenager, or a babysitter, deliberately touched or tried 

to touch your child’s private parts or 

tried to make your child touch or look 

at their private parts, when your child 

didn’t want it? 

These new screening questions accounted for 29,100 

children, or about 10 percent of the total estimate of 

285,400 sexually assaulted children. 

Historical Trends 

NISMART–1, which estimated missing children in 1988, 

did not collect information about sexual assault in a 

way that would allow comparison with NISMART–2 

to examine historical trends. However, data from other 

sources have shown that sexual assault declined during 

the 1990s. According to NCANDS, substantiated sexual 

abuse cases identified by child protective agencies declined 39 percent between 1993 and 1999 (Jones and 

Finkelhor, 2001). NCVS data show a 56-percent decline 

between 1993 and 2000 in sexual assaults self-reported 

by youth ages 12–17 (Finkelhor and Jones, 2004). 

Conclusion 

Because child sexual abuse will continue to be a salient 

concern for law enforcement and the general public, 

there is a clear need to continue to track as accurately 

as possible its true incidence, trends, and the characteristics of victims and perpetrators. The NISMART–2 estimates of child sexual assault provide a benchmark for 

tracking future trends, and NISMART’s interviews with 

adult caretakers and younger children suggest ways of 

measuring the incidence of sexual assault across the full 

spectrum of childhood. 

Table 6: NISMART–2 Estimates of Sexually Assaulted Children, by 

Source of Information 

Information Source Estimate Percent 

All victims 285,400 100 

Self-report (victims ages 12–17) 181,400 64 

Proxy report by caretaker (victims ages 12–17) 51,300 18 

Self-report (victims ages 10–11) 7,000* 2* 

Proxy report by caretaker (victims under age 12) 45,700 16 

Notes: Assaults disclosed by both youth and caretaker are counted as self-reports by the youth. Children younger than 10 were not interviewed; therefore, youth interviews could not disclose assaults 

that occurred before age 9. Estimates are rounded to the nearest 100 and may not sum to the total. 

Percents may not sum to 100 because of rounding. 

*Estimate is based on too few sample cases to be reliable. Another study with the same sample size 

and methodology might produce a very different estimate. 

10 
NISMART 

Endnotes 

1. NISMART–2 definitions distinguish between rape and sexual 

assault (see page 3); the discussion in this Bulletin, however, 

generally uses “sexual assault” as an umbrella term to encompass actual and attempted rapes and other sexual assaults and 

attempted sexual assaults. 

2. Among eligible households with children, the NISMART–2 

cooperation rate was 80 percent and the response rate was 61 

percent. Among youth for whom permission to interview was 

granted, the cooperation rate was 95 percent; the response rate 

for the youth survey overall was 35 percent (.61*.60*.95). The 

American Association of Public Opinion Research (AAPOR) 

defines a response rate as the number of completed interviews 

with reporting units divided by the number of eligible reporting units in the sample; AAPOR defines the cooperation rate 

as the number of cases interviewed divided by the number of 

eligible units ever contacted (AAPOR, 2004). The NISMART–2 

response rate and cooperation rate were computed with 

AAPOR formulas RR4 and COOP2, respectively. 

3. This question was asked only if penetration was not indicated in response to the earlier question. 

4. For definitions, see Finkelhor, Hammer, and Sedlak (2002) 

and Hammer, Finkelhor, and Sedlak (2002). 

5. For further discussion of NCVS methodology, see Fisher and 

Cullen (2004). 

6. The NCVS data for 1999 were also re-analyzed by restricting 

the estimate to sexual assaults experienced by victims ages 

12–17 and computing 95-percent confidence intervals with 

Bureau of Justice Statistics procedures using generalized variance functions for 1999. 

7. 95-percent confidence interval: 117,400–322,100 

(NISMART–2) vs. 41,800–102,400 (NCVS). 

References 

American Association for Public Opinion Research (AAPOR). 

2004. Standard Definitions: Final Dispositions of Case Codes 

and Outcome Rates for Surveys. 3d edition. Lenexa, KS: 

AAPOR. 

Bolen, R.M. 2001. Child Sexual Abuse: Its Scope and Our 

Failure. New York: Kluwer Academic/Plenum Publishers. 

Federal Bureau of Investigation. 2001. Crime in the United 

States, 1999: Uniform Crime Reports. Washington, DC: U.S. 

Department of Justice. 

Finkelhor, D. 1994. Current information on the scope and 

nature of child sexual abuse. The Future of Children 4(2):31–53. 

Finkelhor, D., and Baron, L. 1986. High-risk children. In A 

Sourcebook on Child Sexual Abuse, edited by D. Finkelhor. 

Beverly Hills, CA: Sage Publications. 

Finkelhor, D., Hamby, S.L., Ormrod, R.K., and Turner, H.A. 

2005. The JVQ: Reliability, validity, and national norms. Child 

Abuse and Neglect 29(4):383–412. 

Finkelhor, D., Hammer, H., and Sedlak, A.J. 2002. Nonfamily 

Abducted Children: National Estimates and Characteristics. 

NISMART Bulletin. Washington, DC: U.S. Department of Justice, Office of Justice Programs, Office of Juvenile Justice and 

Delinquency Prevention. 

Finkelhor, D., and Jones, L.M. 2004. Explanations for the 

Decline in Child Sexual Abuse Cases. Crimes against Children 

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

of Justice Programs, Office of Juvenile Justice and Delinquency 

Prevention. 

Fisher, B.S., and Cullen, F.T. 2004. Measuring the sexual victimization of women: Evolution, current controversies, and 

future research. In Criminal Justice 2000, Volume 4: Measurement and Analysis of Crime and Justice, edited by D. Duffee. 

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

Programs, National Institute of Justice. 

Hammer, H., and Barr, M.K. Forthcoming. NISMART–2 Household Survey Methodology Technical Report. Washington, DC: 

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

of Juvenile Justice and Delinquency Prevention. 

Hammer, H., Finkelhor, D., and Sedlak, A.J. 2002. Children 

Abducted by Family Members: National Estimates and Characteristics. NISMART Bulletin. Washington, DC: U.S. Department of Justice, Office of Justice Programs, Office of Juvenile 

Justice and Delinquency Prevention. 

Jones, L., and Finkelhor, D. 2001. The Decline in Sexual Abuse 

Cases. Crimes against Children Bulletin. Washington, DC: U.S. 

Department of Justice, Office of Justice Programs, Office of 

Juvenile Justice and Delinquency Prevention. 

Skogan, W.G. 1986. Methodological issues in the study of victimization. In From Crime Policy to Victim Policy: Reorienting 

the Justice System, edited by E.A. Fattah. Hampshire, UK: 

Palgrave Macmillan. 

Snyder, H.N., and Sickmund, M. 1999. Juvenile Offenders and 

Victims: 1999 National Report. Washington, DC: U.S. Department of Justice, Office of Justice Programs, Office of Juvenile 

Justice and Delinquency Prevention. 

U.S. Census Bureau. 2000. (NP-D1-A) Projections of the 

resident population by age, sex, race, and Hispanic origin: 

11 
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References (continued) 

1999-2100. Washington, DC: Population Projections Program, 

Population Division. 

U.S. Department of Health and Human Services, Administration on Children, Youth and Families. 2001. Child Maltreatment 1999. Washington, DC: U.S. Government Printing Office. 

U.S. Department of Justice, Bureau of Justice Statistics. 2000. 

National Crime Victimization Survey, 1992–1998. Machinereadable data file. Ann Arbor, MI: Inter-University Consortium 

for Political and Social Research, National Archive of Criminal 

Justice Data. www.icpsr.umich.edu/NACJD/NCVS/index.html. 

This Bulletin was prepared under grant number 95–MC–CX–K004 from 

the Office of Juvenile Justice and Delinquency Prevention, U.S. Department of Justice. 

Points of view or opinions expressed in this document are those of the 

authors and do not necessarily represent the official position or policies 

of OJJDP or the U.S. Department of Justice. 

The Office of Juvenile Justice and Delinquency Prevention is a component 

of the Office of Justice Programs, which also includes the Bureau of 

Justice Assistance; the Bureau of Justice Statistics; the Community 

Capacity Development Office; the National Institute of Justice; the 

Office for Victims of Crime; and the Office of Sex Offender Sentencing, 

Monitoring, Apprehending, Registering, and Tracking (SMART). 

Acknowledgments 

David Finkelhor, Ph.D., is Professor of Sociology and 

Director, Crimes against Children Research Center, 

University of New Hampshire, and Advisor to 

NISMART–2. Heather Hammer, Ph.D., is a Senior Study 

Director at theTemple University Institute for Survey 

Research, Philadelphia, PA, and Principal Investigator 

of NISMART–2. Andrea J. Sedlak, Ph.D., is Associate 

Director of Human Services Research at Westat, Inc.; 

Project Director of the NISMART–2 Unified Estimate, 

Juvenile Facilities Study, and Law Enforcement Study; 

and Advisor to the NISMART–2 Household Survey. The 

authors extend their appreciation to the many others 

who contributed to the NISMART–2 project and to 

Barbara Allen-Hagen, OJJDP NISMART–2 Program 

Manager, for her support and guidance. 

Other NISMART Publications 

■ National Estimates of Missing Children: An Overview 

■	 Children Abducted by Family Members: National 

Estimates and Characteristics 

■	 Nonfamily Abducted Children: National Estimates 

and Characteristics 

■	 Runaway/ Thrownaway Children: National Estimates 

and Characteristics 

■	 National Estimates of Children Missing Involuntarily 

or for Benign Reasons 

■	 National Estimates of Missing Children: Selected 

Trends, 1988–1999 

■ NISMART Questions and Answers 

All publications may be downloaded at OJJDP’s Web 

site, www.ojp.usdoj.gov/ojjdp.