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Sexual Assault of Women by Strangers

Guide No. 62 (2011)

by Kelly Dedel

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The Problem of Sexual Assault of Women by Strangers

What This Guide Does and Does Not Cover

This guide begins by describing the problem of sexual assault of women by strangers and reviewing factors that increase its risks. It then lists a series of questions to help you analyze your local sexual assault problem. Finally, it reviews responses to the problem and what is known about them from evaluative research and police practice.

Sexual assault of women by strangers is but one aspect of the larger set of sexual violence-related problems. This guide is limited to addressing the particular harms sexual assaults by strangers cause women. Related problems not directly addressed in this guide, each of which requires separate analysis, include the following:

† See Problem-Specific Guide No. 17, Acquaintance Rape of College Students, for more information on this latter type of sexual assault. Although sexual assaults have commonalities (e.g., the behavior involved, the impact on the victim), sexual assaults by strangers differ from those committed by acquaintances in important ways (e.g., the relationship between the offender and victim; the method of approaching the victim; the protective strategies that can be employed by women to reduce their likelihood of being assaulted). For these reasons, separate Problem-Specific Guides were created.

Some of these related problems are covered in other guides in this series, all of which are listed at the end of this guide. For the most up-to-date list of current and future guides, see www.popcenter.org.

General Description of the Problem

Sexual assault describes offenses in which an assailant forces a victim to participate in a variety of sexual behaviors that may include the actual or attempted penetration of the vagina, anus or mouth with the penis or an object. Legal definitions tend to separate rape, which involves actual penetration, from nonconsensual sexual contact or attempted rape. This guide addresses all types of sexual contact by force.

Most offenders rape to satisfy their need for power and control, and they use various forced sexual acts to do so.1 In other words, the sexual act is the means, rather than the motive, for sexual assault. Although acquaintances commit most sexual assaults, this guide focuses on those that strangers commit. Contact between the victim and the offender is limited to when the assault occurs. Males commit nearly all sexual assaults, and most victims are female.2 Both males and females sometimes sexually assault males, but very little research discusses male victims.† Thus this guide focuses only on female victims.

† Researchers have conducted a few studies of sexual assault against males, including Abdullah-Kahn (2008); Stermac, del Bove, and Addison (2004); and Davies (2002). While underreporting occurs among female victims, it is particularly pronounced among male victims. As a result, our knowledge of the dynamics of sexual assault against males is quite limited.


Unfortunately, the failure of data on sexual assault to make important distinctions and gaps in the research that limit our understanding of the problem hamper this guide. As shown by the statistics below, much of what we believe we know about sexual assault of women by strangers may not be valid because of the comingling of data on stranger and acquaintance rape in the research, when the offenders, victims, and locations (which provide all of the information one needs for good problem-solving) associated with the two types of sexual assault actually differ a lot.

Researchers generate statistics on the prevalence of sexual assault from two main sources: reported crimes and victimization surveys.‡ Researchers estimate that approximately 20 percent of women in the United States have been sexually assaulted.3 Acquaintances assaulted at least three-quarters of these women, while strangers attacked approximately one-quarter of them.

‡ As both of these tend to combine data for rapes committed by strangers and acquaintances, the statistics reported here include both types, unless otherwise indicated.

According to the FBI's Uniform Crime Reports, people reported approximately 89,000 rapes to police in 2008, a rate of 29.3 rapes per 100,000 inhabitants.4 The number of reported rapes has remained relatively stable for the past 10 years, decreasing only 0.5 percent between 1999 and 2008. The rate of reported rapes decreased approximately 11 percent during that same period. However, most researchers agree that statistics relying on reported rapes fail to represent the number of sexual assaults that actually occur in the United States because most victims do not report the assaults to police.5

The National Violence Against Women Survey, completed in 1995 and 1996,6 remains the most rigorous victimization study on the topic. Offenders raped approximately 302,000 women in the year preceding the survey. Someone the women knew raped the vast majority of them (83%). Only 21 percent of respondents raped by strangers reported the attack to the police, meaning that police did not know about nearly 80 percent of all stranger rapes. Although the United Kingdom has a lower incidence of rape, the British Crime Survey has revealed this same rate of underreporting.7 As a result, the number of sexual assaults reported to police reveals only a small fragment of the problem and is unlikely to be particularly helpful to problem-solving efforts. To accurately understand the problem, communities must first understand and address the issues underlying victims' reluctance to report sexual assault to police.

Underreporting by Victims

Without knowing offenses have occurred, police cannot identify and arrest suspects, and prosecutors cannot prosecute offenders. The criminal justice system's deterrent value is lost. Further, in cases of sexual assault by a stranger, the victim is often the only witness. The victim's cooperation is therefore essential to an effective criminal justice response. Police would have substantially more information about the dynamics of sexual assault by strangers, and how to prevent them, if they could encourage more victims to report their assaults.

Women choose not to report their rape to police for many reasons.8 Some feel partially responsible, ashamed, or embarrassed about what happened to them. Others may have been engaged in illegal activity (e.g., drug use, prostitution, underage drinking) when the assault occurred and worry that police will treat them insensitively. Some are concerned their involvement in the criminal justice system will be burdensome. Still others fear retribution from the offender. While these barriers to reporting are not insurmountable, they will likely require strategies specifically designed to help victims overcome them.

The research literature indicates that women are more likely to report their victimization when they have actively resisted the attack, when the assailant has physically injured them, or when the assailant used a weapon or forced them to participate in particularly depraved acts. These factors may help women to define what happened to them as an assault.9 Further, those who seek medical treatment promptly and who believe their family and friends will support their decision to report their assault to the police are more likely to do so.10

Victims' Experiences With Police

Much literature discusses sexual assault victims' experiences with the police who handled their cases when they chose to report. While several studies show that victims' experiences with police have improved in recent years, negative interactions continue to occur.11 Sometimes called the "second victimization," poor treatment by police has been said to increase the distress, alienation, and self-blame that many victims experience. Studies of police interviews with sexual assault victims have found fault with officers who question victims about their clothing, alcohol or drug use, resistance level, prior sexual encounters, and sexual responses to the assault.12 In other words, when police use the "Why not?" form of questioning (e.g., "Why didn't you scream? Fight back? Tell anyone?"), the self-blame that already burdens many victims increases.13 Victims have also complained that police seemed reluctant to take the report and/or to refer them for a forensic evaluation, or that police otherwise implied that the case was not serious.14

Challenges for Acknowledging the Problem

Perceptions about what constitutes "real rape" affect how police, prosecutors, judges, juries, and the general public view the problem of sexual assault. Common distortions include the following:

  • Beliefs that the victim may be partially to blame for the assault (e.g., the victim provoked the attack through her appearance, behavior, or sexual history)
  • Beliefs that the offender may not be fully responsible for his behavior (e.g., the male sex drive is difficult to control)15

In addition, the regrettable problem of false reporting may also affect how police view alleged victims. Some victims may be unsure of the details, confused as a result of their use of drugs or alcohol, or lying about some aspect of the experience, but may be truthful about the general fact they were assaulted. While most police have experienced an alleged victim who falsely reports a sexual assault, the professional literature on the topic is very sparse. Many researchers fear addressing the topic because it is politically risky to do so.16 Researchers widely cite a 2 percent false- reporting rate for sexual assault in commentary on the subject; however, scientists have thoroughly investigated this claim and found that the research does not support it.17 The two research studies that have examined the issue cite very different rates of false reporting (17 percent and 50 percent).18 Unfortunately, as most research on sexual assault has done, these studies comingled data on sexual assaults by strangers and those by acquaintances.

Researchers have more widely examined the motives for false reporting. They have found that a need for attention from friends or significant others, a desire to access medical treatment for sexually transmitted diseases or pregnancy, or an attempt to explain an inappropriate absence to a significant other or parent has motivated women to falsely report sexual assaults.19

Distortions about what constitutes "real rape" and the problem of false reports of sexual assault make it difficult for some communities to acknowledge the true extent of their sexual assault problem. Not only can they lead to biases in how police and prosecutors handle reports of sexual assault, but also false reports add imprecise data to measures of the prevalence of sexual assault.

Harms Caused by Sexual Assault

In varying degrees, victims experience emotional, physical, social, and sexual problems as a result of being sexually assaulted. Some women suffer severe injuries, contract sexually transmitted diseases, or get pregnant.20 Nearly all women experience psychological anguish, and many experience Posttraumatic Stress Disorder at some point in their lives.21 In the short term, most women experience some combination of fear and anxiety; denial, shock, and disbelief; guilt, hostility, and blame; and feelings of helplessness or a loss of control.22 Longer-term effects may include disturbances in eating and sleeping; strained relationships with family, friends, and partners; difficulty maintaining employment; and sexual problems.23 Recovering from these effects requires support from helping professionals, friends, and family and may take a long time.

Factors Contributing to Sexual Assault of Women by Strangers

Understanding the factors that contribute to your problem will help you frame your own local analysis questions, determine good effectiveness measures, recognize key intervention points, and select appropriate responses. Because so many sexual assaults go unreported to police, data on offender and victim characteristics and locations and times when sexual assaults by strangers occur are very limited and may be misleading. You will need additional information from local victimization studies, rape crisis centers, and hospitals to fully understand your problem.

The sexual assault analysis triangle below may help to frame the important factors contributing to the problem. Rather than being determined by a single factor, sexual assault may result when (1) a motivated offender and (2) a vulnerable victim cross paths in (3) a location without capable guardians. Depending on the nature of your local sexual assault problem, each triangle side's relative importance will vary. You may be able to reduce sexual assault by addressing one triangle side (e.g., providing programs for women designed to reduce their vulnerability to an attack), but you will likely have better results if you identify responses that simultaneously target offenders, victims, and locations where sexual assaults are likely to occur.

Figure 1. Sexual Assault Analysis Triangle.†
Fig. 1. Sexual assault analysis triangle.

† The problem analysis triangle originates from routine activity theory, which posits that for a crime to occur, a motivated offender is present, a suitable target (victim) is available, and no suitable guardian is around to prevent the crime. See the Problem-Oriented Policing Center website, www.popcenter.org, for more information on routine activity theory.

Sexual Assault Phases

How offenders plan or commit sexual assaults highlights situational characteristics that can inform prevention efforts. Transactions during sexual assaults are usually unstable given that the offender must maintain control over the victim and manage situational variables to continue the assault. Researchers developed the specific phases of sexual assaults discussed below through interviews with incarcerated rapists who were strangers to their victims.24

First, most sexual offenders have a series of preexisting life problems and tensions and have trouble coping with everyday life. These personally troubling events generally become particularly severe immediately before the assault. A specific event may increase the perpetrator's sense of futility and anger and may heighten his motivation to offend.

This motivation then transforms into action. The offender may be determined to rape someone from the outset or may decide to assault a woman encountered some other way (e.g., by providing help, through a social encounter, or during another crime). Some offenders choose victims simply because they are there, while others choose victims because they have specific characteristics that are meaningful to the offender. Some offenders initiate the attack impulsively, while others ensure the surroundings are appropriate and then wait for a suitable victim to emerge.

Once the offender targets a victim, he engages her, either verbally or physically, to gain control. The sudden, unexpected confrontation gives the victim little opportunity to decide whether and how to resist. Once offenders establish control of their victims, most offenders struggle to gain control of their own emotions while conducting the assault. During this time, they will usually either physically dominate the victim or negotiate cooperation verbally.

Most assailants do not have weapons during the assault.25 They are far more likely to threaten physical harm and to punch or slap victims. Although offenders sometimes injure their victims with weapons, they tend to use weapons to control and to inhibit resistance rather than to physically harm the victim.26

Finally, the offender must leave the scene. Many simply flee without any organized activity to conceal their actions or their identity. Others may threaten to retaliate if the victim reports the crime and may take steps to destroy evidence.

Dissecting the various phases of the assault highlights areas in which potential victims could be better protected. Further, the locations where sexual assaults are likely to occur could be adapted to make assaults more difficult to commit.


The National Violence Against Women Survey found that slightly more nonwhite women reported having been raped in their lifetime than white women (20% versus 18%, respectively) and that rape occurs at an early age.27 Just over half of the women reported their first rape occurred before they were 18. Thirty percent were raped between the ages of 18 and 24, and 17 percent were raped at age 25 or older.

In both the United States and the United Kingdom, young, unmarried women are the most common victims of sexual assault, although their vulnerability may result from their being more likely to associate with younger men or to frequent risky places.28 You should interpret these data with caution because they combine victims of sexual assaults by both strangers and acquaintances.

Offenders may pick a victim at random, simply because she is available. Other offenders may select a victim because she has certain characteristics (e.g., ethnicity, hair color, size, dress style) that symbolically represent something that has angered him. Women who are alone and appear to be distracted or otherwise unaware of their surroundings (e.g., talking on a cell phone, intoxicated, lost) may be easier to approach undetected and to overpower.


Studies of incarcerated rapists indicate that younger men generally commit sexual assaults against strangers.29 Most researchers believe that rapists have generally negative or adversarial attitudes toward women. Although they may have had difficulty sustaining adult relationships, the offenders studied usually had access to consensual sexual partners.30 Offenders who participated in research on sexual assault often exhibited a sense of sexual entitlement, need for power and control, hostility and anger, and acceptance of interpersonal violence of all kinds.31 Studies of incarcerated rapists have also found that a large proportion had at least one previous conviction, although it was generally not for a sex offense and tended to be for a violent crime, burglary, or theft.32 Among those studied, most rapists were not exclusively sex offenders. However, those who were convicted of a sex offense were far more likely than other offenders to commit a subsequent sex offense.33

Locations and Times

The rate of reported sexual assaults is highest in cities outside of major metropolitan areas and lowest in nonmetropolitan areas.34 Unfortunately, victimization studies do not collect data on the locations where assaults occur. A study of incarcerated stranger rapists in the United Kingdom found that nearly two-thirds of the assaults occurred in public places, including parks, deserted streets, public buildings, and bars and nightclubs. Smaller proportions occurred in the perpetrator's or the victim's home.35

Most researchers believe that sexual assaults take place in relatively isolated areas where the risk of intervention by bystanders is limited. One study of convicted rapists found that they committed most sexual assaults near their homes.36 Further, perpetrators were more likely to travel greater distances when they had targeted a specific location with a lot of suitable victims. Some attacked their victims in areas close to a previous residence because they were familiar with the neighborhood. Finally, some offenders spent considerable time prowling a targeted area, searching for a suitable victim. While unfortunately we know little about offenders' connections to the places where sexual assaults occur, this relationship has important implications for problem-solving.

Most sexual assaults occur at night, under the cover of darkness and when fewer people are out in public. Intoxicated bar patrons, women who work late, or women who take night classes may travel home alone at night.

Alcohol Use

The use of alcohol, particularly in bars or other public places, increases the risk of sexual assault in two ways. First, researchers believe alcohol decreases men's inhibitions against using violence and increases their sexual interest, and thus their propensity to commit rape.37 Second, when intoxicated, women may pay less attention to cues that would normally alert them to potentially dangerous situations. As a result, they may fail to take precautions or may take risks that they would not otherwise take (e.g., walk home alone, accept a ride from a stranger).38 Further, a victim's ability to resist an attack is compromised when she is intoxicated. In most cases of sexual assault by strangers where alcohol is involved, the victim voluntarily drinks and is not drugged or rendered intoxicated by the attacker.39

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