Keywords

“Women don’t do such things!” (Wijkman, Bijleveld, & Hendriks, 2010) is a declaration that accurately captures societal and cultural resistance to recognizing that women commit sex crimes. Historically, sexual offending has largely been associated with men for various reasons. In part, this association is driven by public panics that stem from intense media depictions of male sexual offenders who commit serious, albeit rare, sex crimes such as a rape-murder against strangers, specifically children victims (Jenkins, 1998; Zgoba, 2004). In addition, the observation that women sexually offend goes against normative sexual scripts we ascribe to gender, such as the stereotype that women are sexually passive and are unwilling, or possibly unable, to commit such crimes due to their delicate and nurturing nature (Denov, 2003, 2004a). In contrast, men are viewed as possessing stronger sexual drives as well the physical capability to carry out such crimes, which is a more intuitive logic that explains their sexual offending (Denov, 2003, 2004a). Given the historical resistance to recognizing female sexual offending, a recent study found approximately 65% of respondents disagreed or strongly disagreed that female-perpetrated sex crimes were less serious than sex crimes committed by men (Cain, Sample, & Anderson, 2015). This suggests public perceptions of female sexual offenders are shifting. It is unknown whether these perceptions are driven by media depictions of female sexual offenders, but it highlights that the public is beginning to recognize the severity of sex crimes committed by women.

Beginning in the 1980s and early 1990s, the focus on sex crimes slowly shifted to include discussions about and research on female sexual offenders (FSOs), their crimes, and their victims. Within the last decade, this body of knowledge has expanded greatly; more than in the previous 30 years combined (Cortoni, 2015). In light of developments in the field, scholars now are calling for a gender-specific approach toward FSOs because research has uncovered inherent differences between women and men who sexually offend, such as offending behavior and recidivism rates (Gannon & Cortoni, 2010). This has led to a growing body of literature that provides new insights about women who commit sex crimes. Even with this surge in research and scholarly activity, our knowledge of females who sexually offend is still in its infancy compared to what we know about their male counterparts.

While official crime statistics like the Uniform Crime Reports (UCR) show the majority of sexual offenses are committed by men, women perpetrators account for a sizable amount of sex crimes. More importantly, beyond numbers, these crimes have serious short-term and long-term consequences for sexual abuse victims (Deering & Mellor, 2011; Tsopelas, Tsetsou, Ntounas, & Douzenis, 2012). Self-report studies where victims are asked about the effects of female-perpetrated sexual abuse report psychological impairment, mental health issues, sexual/intimacy problems, substance abuse problems, and self-harm such as self-mutilation and suicide attempts (Deering & Mellor, 2011; Denov, 2004b; Dube et al., 2005; Tsopelas et al., 2012). Based on the best evidence, although women who sexually offend are the minority, the consequences for their victims are significant and suggest sexual offenses committed by women is a critical concern. For professionals, practitioners, and students to gain a better understanding about women who sexually offend, this chapter addresses the following topics: sociodemographic characteristics of FSOs and their victims; the prevalence of female sexual offending, including recidivism rates of FSOs; typologies of FSOs; group composition and offending behaviors; and the criminal justice system’s response to this population.

Who Are Female Sexual Offenders?

Like male sexual offenders, females who sexually abuse are a heterogeneous population ; there is no one “one size fits all” type. While the media typically tends to focus on high-profile cases of female school teachers who have sexual relations with their younger male students (Knoll, 2010), there are a variety of female sexual offenders who go beyond this offense narrative. Based on prior research, there are some overarching characteristics of FSOs from which we can make some generalizable statements. Although these are patterns that have been identified in the literature, FSOs have a variety of sociodemographic characteristics . In addition, different samples of FSOs, for example, from the criminal justice system versus a clinical setting, will yield different characteristics. Keeping this caveat in mind, this section will help readers visualize what might be described as a “typical” FSO. It is unknown how many FSOs are living in communities who have yet to be identified by social services or the criminal justice system, especially given there is still a cultural resistance to recognize that women commit sex crimes.

Characteristics of Female Sexual Offenders

Women who sexually offend have been found to be, on average, in their mid- to late-20s or early 30s (Budd, Bierie, & Williams, 2017; Ferguson & Meehan, 2005; Gillespie et al., 2015; Sandler & Freeman, 2007; Williams & Bierie, 2015). In two studies that have the largest sample size to date of female-perpetrated sexual assault incidents, the average age of female sexual offenders who offend alone (solo FSOs), was approximately 26 years old (Budd et al., 2017; Williams & Bierie, 2015). This average was based on data from 37 states that spanned 21 years. While this implies young adult to middle-aged offenders, studies document that female sexual offenders can range from juvenile offenders as young as 10–11 years of age, to elderly offenders who are in their 60s and 70s (Fazel, Hope, O’Donnell, & Jacoby, 2002; Levenson, Willis, & Prescott, 2015; Vandier & Kercher, 2004; Vandiver & Teske, 2006).

There is consistent evidence that FSOs are predominately Caucasian (Ferguson & Meehan, 2005; Sandler & Freeman, 2007; Vandier & Kercher, 2004; Williams & Bierie, 2015). While there is some fluctuation on the percentage depending on study sampling, most scholars report Caucasians make up anywhere from 75% to 90% of FSOs. Williams and Bierie (2015) found that approximately 81% of their sample was Caucasian or Hispanic, 18% was Black, and 1% was of another race, specifically Asian or Native American. Due to the source of their data, (the National Incident Based Reporting System or NIBRS), Caucasian and Hispanic subjects were combined; nevertheless, their findings support descriptions of the racial characteristics of FSOs that have been reported in other studies. For instance, Vandier and Kercher (2004) and Sandler and Freeman (2007) had similar percentages in their research: 83–88% Caucasian, 12–16% Black, and about 2% another race.

Research also supports that women who sexually offend have high levels of early life and lifetime trauma. These traumas range from emotional abuse or neglect (Levenson et al., 2015; Strickland, 2008; Wijkman, Bijleveld, & Hendriks, 2010), physical and/or psychological abuse (Kaplan & Green, 1995; Strickland, 2008; Wijkman et al., 2010), a history of sexual abuse (Wijkman et al., 2010), childhood sexual abuse (Gannon, Rose, & Ward, 2008; Johansson-Love & Fremouw, 2009; Kaplan & Green, 1995; Levenson et al., 2015; Lewis & Stanley, 2000; Turner, Miller, & Henderson, 2008), and childhood physical abuse (Gannon et al., 2008). Evidence also indicates FSOs are likely to suffer from mental health issues, such as posttraumatic stress disorder, anxiety disorder, and personality disorders, and they are more likely to have substance abuse problems (Faller, 1995; Mathews, Matthews, & Speltz, 1991).

In a recent study, Levenson et al. (2015) investigated a sample of 47 U.S. FSOs recruited from outpatient and secure sex offender treatment programs to assess their adverse childhood experiences (ACE) . They then compared these offenders’ ACE scores to those of women in the general population. Their survey captured various types of mistreatment prior to the age of 18: emotional, physical, and sexual abuse, emotional and physical neglect, and household dysfunction such as domestic violence, divorce, or a household that had a substance-abusing, mentally ill, or incarcerated household member. Overall, FSOs compared to the general female population had much higher rates of child sexual abuse (more than three times the odds), verbal abuse (four times the odds), and emotional neglect (more than three times the odds) (Levenson et al., 2015). Female sexual offenders were also more likely to experience sexual abuse and emotional neglect in childhood compared to their male counterparts (Levenson et al., 2015).

Victims Characteristics of Female Sexual Offenders

Pertaining to victim characteristics, stranger victimizations by females are rare, typically accounting for less than 10% of victimizations (Budd et al., 2017; Wijkman et al., 2010; Williams & Bierie, 2015). While there is an expansive age range of victims (from infants to adults), research indicates the mean age of victims for FSOs is somewhere around 12 years old (Budd et al., 2017; Ferguson & Meehan, 2005; Sandler & Freeman, 2007; Vandier & Kercher, 2004; Wijkman et al., 2010). For example, Ferguson and Meehan (2005) found that almost 70% of the victims were between the ages of 12 and 16, 15% were under 12, and 1% were adults. In contemporary research, Budd et al. (2017) found that solo female sexual offenders victimized youth who were approximately 12 years old, on average. Depending on whether the female offended alone or with others, the average age of victims spanned from approximately 12 years old to 16 years old (Budd, 2017).

Victim gender selection patterns for women who sexually offend are less straightforward than victim gender selection patterns of male sexual offenders, or, as stated by Johansson-Love and Fremouw (2009), it seems FSOs are less discriminating when it comes to victim gender. While male sexual offenders have a much higher propensity to offend against females (Williams & Bierie, 2015), there does not seem to be a direct and clear preference for a victim gender based on data derived from sexual assaults committed by FSOs. For instance, Williams and Bierie (2015) and Budd et al. (2017) found that solo female offenders victimized males in approximately 54–55% of the reported sexual assault incidents and victimized females in approximately 42–43% of the sexual assault incidents. Wijkman et al. (2010) had similar findings in that 60% of their sample of female sexual offenders abused a female, whereas 31% abused a male. In contrast, other studies suggest male victims are more likely to be sexually abused by women. Using a sample of FSOs from New York State, Sandler and Freeman (2007) found that approximately 57% of the victims were male and 34% of the victims were female. Vandiver (2006) also found that 63% of her sample of solo FSOs offended against males. Given the state of findings on victim gender, FSOs are more likely to have victims of either gender compared to male sexual offenders who have been found to favor female victims.

In summary, based on a culmination of evidence, the typical woman who sexually offends is likely Caucasian and in her 20s or 30s. Victims are most likely known to the offender, and there is consistent data that stranger victimizations are rare. There is a lack of victim gender preference, although this could change as research on victim selection is ongoing. Compared to the general population , FSOs have suffered a host of trauma. It seems these traumas affect female sexual offenders to a greater extent that those in the general population, the traumas begin at a young age, and the traumas often persist throughout adulthood.

Female Sexual Offending: The Numbers

Multiple sources provide estimates of the number of women who sexually offend, such as government-derived crime data and statistics produced by researchers who study FSOs. While each source provides information on the number of FSOs, consumers of these numbers should keep in mind that each of these sources has their own strengths and limitations. As with other types of offenses, there is the “dark figure” of crime—crimes that do not get reported to the police nor result in an arrest and are therefore “missing” from crime statistics. As a result, researchers and government agencies conduct victimization surveys to gather additional data on sexual abuse committed by women. While these methods complement official crime statistics, they too suffer from limitations such victims’ unwillingness or inability to disclose their abuse. In addition, historically and contemporarily, underreporting is prevalent for sexual offenses compared to other crime types (Berzofsky, Krebs, Langton, & Smiley-McDonald, 2012). There is also evidence that victim reporting of sexually based crimes has continued to decrease (Planty, Langton, Krebs, Berzofsky, & Smiley-McDonald, 2013). Taken as a whole, statistics that document female sexual offending are likely undercounts. That is not to say the number of females would equal or outnumber males who commit sex crimes, but the estimates of females who sexually offend are likely higher, to some extent, than what is recorded based on the available data.

Pertaining to official crime statistics, the UCR , a prominent source of crime statistics in the USA, collects data on rape arrests and arrests for other sexual offenses. Of the 10,471 arrests for rape, 1.6%, or 168 perpetrators , were female whereas 98.4%, or 10,303 perpetrators, were men (FBI, 2013). Of the 35,604 arrests made for other sex offenses, 2657 (7.5%) subjects were female and 32,947 (92.5%) were men (FBI, 2013). Although the UCR depicts low rates of female sexual offending in comparison to men, victims of female sexual offenders have been less likely to report their victimization to police, and law enforcement has been significantly less likely to make arrests in these cases (Angelides, 2008; Lawson, 1993; Williams & Bierie, 2015). Second, sex crimes by females are less likely to be recorded in arrest data even if they are detected. For example, until 2012, the UCR defined rape as a sex crime that involved a female penetrated by a penis using force. This specific definition leaves sex crimes by females disproportionately uncounted relative to male offenders because of female sexual offender’s anatomy, their sexual assault behavior, and the gender of their victims (Bierie & Davis-Siegel, 2014).

It is no surprise, then, that research using self-report data from victims of sexual assault show substantially higher prevalence rates for female sexual offending (Black et al., 2011; Dube et al., 2005; Green, 1999). In particular, victim surveys tell a different story compared to official statistics about the number of females who sexually abuse. Green (1999) found that 6–15% of abused girls and 14–24% of abused boys were sexually abused by a female. Child abuse self-report studies have found somewhat similar statistics, reporting that 6% of women and 39% of men have experienced child sexual abuse by a female perpetrator (Dube et al., 2005). According to the 2010 National Intimate Partner and Sexual Violence Survey (NISVS) , a nationally representative survey of adults in the USA that measures sexual violence, intimate partner violence, and stalking, there is a substantial percentage of women and men who have experienced sexual assault by a female over the course of their lifetime. When estimating the lifetime prevalence of rape, females reported that 2% of their rapists were women (Black et al., 2011). For other types of sexual violence, female victims reported approximately 8% of their perpetrators were women (Black et al., 2011).

Also, according to the NISVS, men were more likely than women to report female perpetrators of sexual violence over the course of their lifetime. Approximately 7% of male rape victims reported female perpetrators (Black et al., 2011). Other types of sexual violence were more likely to be perpetrated by women against men: being made to penetrate someone else using force or threats of force (79.2%), sexual coercion using nonphysical pressure (e.g., threatening to end the relationship) that leads to penetration (83.6%), and unwanted sexual contact such as sexually fondling body parts (53.1%) (Black et al., 2011). There was also a high percentage of female perpetrators in noncontact sexual experiences, such as exhibitionism or masturbating in front of the victim. Approximately 38% of male respondents reported female perpetrators during these noncontact crimes.

In one of the most comprehensive prevalence studies to date, Cortoni, Babchishin, and Rat (2017) estimated that approximately 2–12% of sexual offenses are committed by women. By conducting a meta-analysis, they estimated this proportion of female sexual offenders using official crime data and victimization surveys from 12 countries. Crime statistics (i.e., those reported to police) produced a fixed-effect average of 2.2% of sexual offenders who were women and victimization surveys produced a fixed-effect average of 11.6% of sexual offenders who were women. Based on their estimates, they also concluded that sex offending among female juveniles is more common compared to sex offending among female adults (Cortoni et al., 2017). In general, given various sources of data and differing methodologies used in prevalence studies, in combination with the underreporting of sexual crimes to official sources like the police, their meta-analysis showed that the proportion of females who sexually offend is higher than previously thought.

Recidivism

While prevalence studies help us to better comprehend the number of women who sexually offend, recidivism studies help criminal justice and community actors, like treatment providers, assess the likelihood a particular offender will commit another sex crime after being adjudicated for a sexual offense. This is type of risk assessment can be valuable for policy makers and criminal justice actors as they address the propensity for women to repeatedly sexually offend after official detection by the criminal justice system (Sandler & Freeman, 2009). If research and assessment tools can help us better identify who is at a higher risk for reoffense, for example male or female sexual offenders, then different social controls may be put into place to stem opportunities for recidivism.

There are a limited number of studies addressing recidivism rates for female sexual offenders. The paucity of studies is attributable in large part to the difficulties obtaining a large enough sample size to conduct the necessary statistical analyses, particularly given that female sexual offenders seem to have very low rates of sexual recidivism (Cortoni & Hanson, 2005; Cortoni, Hanson, & Coache, 2010; Poels, 2007; Sandler & Freeman, 2009). Cortoni and Hanson (2005) used six data points, including published and unpublished research and official recidivism data, to gauge the level of recidivism for 380 women who committed violent and or sexual offenses and then went on to reoffend. Recidivism was tracked for an average 5 years. Within that time frame, they found approximately 1% of women recidivated with a sex crime. They also calculated recidivism for violent crimes and an overall percent for any type of recidivism. Approximately 6% of female sexual offenders committed another violent offense and about 20% overall recidivated with any type of offense.

Sandler and Freeman (2009) assessed recidivism with a sample of 1466 females convicted of sexual offenses in New York State and investigated factors associated with sexual recidivism with this group of offenders. Unique to their analysis was that they tracked recidivism over three time periods: 1, 3, and 5 years. This type of method can help establish trends over time. Of the 1466 female sexual offenders, 2.2% were rearrested for another sex crime. As time passed, the risk for sexual recidivism increased although the increase was extremely small: 0.8% at 1 year, 1.3% at 3 years, and 1.8% at 5 years. It is important to note that follow-up times are from the date of conviction. Sandler and Freeman (2009) explain that due to the structure of the criminal history files they could not assess recidivism from time of release into the community. However, a large majority of their sample (about 72%) received probation, meaning their sentence was served within the community in lieu of incarceration. For those who sexually recidivated, what factors significantly predicted rearrest for a sexual offense? They found sexual recidivism was significantly associated with additional child victim convictions that occurred prior to the sexual assault conviction, additional misdemeanor convictions prior to the sexual assault conviction, and increased offender age (Sandler & Freeman, 2009). With their sample, certain demographic characteristics and criminal conviction history mattered in explaining women’s propensity to sexually reoffend.

Because of the difficulty obtaining large sample sizes of FSOs, scholars have conducted meta-analyses to address female sexual offender recidivism rates. Cortoni et al. (2010) used this technique to assess recidivism for a sample of 2490 female sexual offenders who were tracked for an average of 6.5 years. Their study defined recidivism broadly: arrest, charged, convicted, or incarcerated for a new sexual offense. Approximately 3% of their sample recidivated sexually. Based on the limited number of studies that address recidivism for female sexual offenders, the overall finding is that their likelihood to sexually recidivate is exceptionally low; within approximately 7 years between 1% and 3% of female sexual offenders will reoffend sexually.

Typologies of Female Sexual Offenders: A Framework for Understanding Patterns

While prevalence data and recidivism data give us one layer of insight into females who sexually offend, sexual offending in general is a much more dynamic process than what is portrayed by crime statistics. It is not only about the number of women who sexually offend and the number of women who will sexually offend again after they are identified by authorities. Rather, it is the entirety of the sexual offense process that can help to us better understand the etiology of female sexual offending. Therefore, researchers have begun to create typologies—empirically driven ideal types based on qualitatively or quantitatively derived clusters of offenders who share the same or highly overlapping features. In addition to their ability to identify the causes and or motivations of females who sexually offend, typologies can help us better understand offense characteristics such as victimology (Sandler & Freeman, 2007). It is important to remind readers of the heterogeneity of the population of female sexual offenders. While typologies provide valuable information that can inform policy and practice, not all female sexual offenders will neatly fit into one of these identified clusters, or types.

Mathews, Matthews, and Speltz (1991) were among the earliest researchers to attempt to create a typology to better understand female sexual offenders. Various authors have stated that their typology is one of the more useful and most cited typologies (Nathan & Ward, 2002; Sandler & Freeman, 2007; Vandier & Kercher, 2004), and their efforts laid the foundation for future researchers. Based on data from a small clinical sample, Mathews and colleagues (1991) were able to qualitatively analyze extensive interview data that was gathered over the course of a year. Three main categories of female sexual offenders emerged based on crime characteristics , perceptions of victims, if the offender had a male co-offender, and psychological characteristics: the teacher/lover, the predisposed offender, and the male-coerced offender.

The “teacher/lover” has a severe history of emotional, physical, and sexual abuse, has a strong likelihood of substance abuse, prefers male victims, but denies her abusive behavior is criminal due to her perception she is teaching her male victim(s) about sexuality and that the victim(s) desire the experience (Mathews et al., 1991). The “intergenerationally predisposed” offender suffers from addictive behaviors, low self-esteem, passivity, and intense anger, has a history of sexual abuse by family members and caretakers, prefers to sexually abuse young family members, and attributes her behavior to an attempt to achieve emotional intimacy (Mathews et al., 1991). The “male-coerced” offender has a history of childhood sexual abuse by male offenders and is described as dependent and nonassertive with very low self-esteem. In adulthood, the male-coerced offender maintains relationships with abusive men who sexually abuse her children; she participates in the abuse due to reasons such as fears her partner will leave her, or fear of physical abuse at the hands of her partner (Mathews et al., 1991). Scholars also have identified women who willingly participate in the abuse, the “male-accompanied” offender, who are motivated by anger and jealousy toward the victim (Mathews et al., 1991; Nathan & Ward, 2002).

Vandier and Kercher (2004) constructed six typologies with one of the largest sample sizes to date, 471 female sexual offenders in Texas. The “heterosexual nurturer,” such as those in mentorship or caretaking roles, is, on average, 30 years of age. She only victimizes males, and her victims, on average, are about 12 years old. This cluster coincides with Mathews et al.’s (1991) teacher/lover offender. The “noncriminal homosexual offender” is, on average, 32 years of age, victimizes almost exclusively females with an average age of 13, is unlikely to have a criminal history, and is the least likely to commit sexual assault. The “female sexual predator” is, on average, 29 years of age, victimizes primarily males with an average age 11, and has a high likelihood to sexually recidivate. The “young adult child exploiter” is, on average, 28 years of age, is most likely to commit sexual assault, and victimizes young children with an average age of seven, with whom she has had a prior relationship. This type of offender may reflect Mathews et al.’s (1991) predisposed offender. The final two types are adult offenders who victimize adults. Both offenders and victims have average ages in their 30s. The “homosexual criminal” has a high rate of arrests and commits crimes of “forcing behavior” (e.g., prostitution) possibly for financial gain (Vandier & Kercher, 2004). The “aggressive homosexual offender ” likely has a preestablished relationship with her victim, who is also, on average, in their early 30s. She is the most likely to commit sexual assault.

Since these foundational studies, other scholars have used a variety of data sources to either test existing typologies or create new typologies. For instance, Sandler and Freeman (2007) tested Vandier and Kercher’s (2004) typology using a sample of FSOs from New York State. They, too, found six distinct typologies, two of which overlapped with Vandier and Kercher’s (2004) research: the heterosexual nurturers and young adult child exploiters. Wijkman et al. (2010) assessed a sample of FSOs from the Netherlands and identified four offender types. Their prototype rapist resembled Vandier and Kercher’s (2004) female sexual predator (Wijkman et al., 2010). In addition, their prototype of “passive” mothers resembled Mathews et al.’s (1991) male-coerced offender and, to a lesser degree, the predisposed offender (Wijkman et al., 2010). While there exists some overlap among these studies, the diversity of clusters found using different samples of female sexual offenders highlights the heterogeneity of FSOs and the continuing work that needs to be done to understand their offending behavior.

Pathways to Offending

In an attempt to move beyond typologies, groups of scholars have started to map offense processing characteristics of FSOs to formulate a temporal model that includes cognitive, behavioral, affective, and contextual factors. Gannon et al. (2008) call their temporal model the “descriptive model of female sexual offending” (DMFSO) . To develop the DMFSO, they recruited 22 women in England who had sexual offense convictions or strong sexual elements to their crimes. Their data consisted of general offense data, demographic data, and interview data. The interviews were conducted with the women in the form of what one might consider a life course interview pertaining to sexual offending: influencing factors in childhood and early adulthood, factors related to the pre-offense and offense period, and factors that occurred directly post-offense (Gannon et al., 2008). Using qualitative methodology, they created a temporal sequence that then spanned these background factors, the pre-offense period, and the offense and post-offense period.

Pertaining to background characteristics (Phase 1 of the DMFSO), the women either had positive or negative early family environments during childhood or adolescence; for example, parental neglect or family cohesion. Gannon et al. (2008) note that some of these negative early environments improved, while other positive environments deteriorated. All but five of the women reported experiencing sexual, physical, or emotional abuse during their childhood and adolescence. Approximately 50% experienced more than one type of abuse. Building the temporal sequence, Gannon et al. (2008) then assessed lifestyle outcomes in late adolescence and early adulthood. They found there was either a maladaptive lifestyle driven by deviant peers, childhood abuse, and antisocial cognitions about violent and sexual norms; or an adaptive lifestyle. Most women experienced vulnerabilities, such as poor coping styles, for example, alcohol or substance abuse, and poor social support. They also exhibited vulnerability through poor mental health and or personality traits such as aggressiveness and dependency. Vulnerability factors contributed to early adult lifestyles that Gannon et al. (2008) stress became risk factors for offense for many women later in the DMFSO. The final component of Phase 1 consists of early adulthood major life stressors. The vast majority, 20 women, experienced domestic abuse (physical, emotional, or both). Some of their male partners also began grooming them during this phase to sexually offend.

The pre-offense period is Phase 2 of the DMFSO . Gannon et al. (2008) argue that due to the culmination of the background characteristics in Phase 1 many of the women were already at an elevated risk to sexually offend. Within this phase there are four stages that lead up to the offense phase: unstable lifestyle (typically 1 year to 6 months before the offense), goal establishment, distal planning, and proximal planning (planning directly before the offense). By this phase in the temporal model all the women in their study had an unstable lifestyle. It is within this time frame that the women began to create goals to offend and began distal planning. These stages—goal creation and distal planning—occurred simultaneously or occurred very closely together (Gannon et al., 2008). Goals for sexually offending included sexual gratification, intimacy, and “other” instrumental reasons such as revenge/humiliation or financial gain (Gannon et al., 2008). A small minority (three women) had no goals and offended out of extreme fear of their abusive partner.

During this phase, distal planning occurs in three different ways: implicit planning where “the individual engage[s] in a form of self-deception, subtly adjusting circumstances in a manner highly likely to increase their chances of physical and/or emotional contact with the victim”; explicit planning where women “explicitly set out to offend against their victims either sexually of nonsexually”; and directed planning where women are coerced to sexually offend by a male co-perpetrator (Gannon et al., 2008, p. 364). The last stage of Phase 2 is proximal planning or planning that happened immediately before the offense occurred. Gannon et al. (2008) found three dominant proximal planning strategies: implicit disorganized, or women who are most likely implicit planners and then become impulsive and disorganized immediately prior to the offense; directed proximal, or women who execute plans based on direction from a male co-offender; and explicit precise, or women who take part in group offenses where they typically execute a distal explicit plan “with exact military precision” (p. 365) to humiliate their victim, to exact revenge on him or her, or for financial gain.

The last phase, Phase 3, of the DMFSO is the offense and post-offense period consisting of the offense approach, the offense behavior, the victim’s response, the offense consequences, and the offense outcome. There are four main offense approaches: maternal approach, maternal avoidant approach, aggressive approach, and operationalized approach. According to Gannon et al. (2008), maternal approaches are used by women who are coercive, nonaggressive, and do not intend to offend but take no additional actions to avoid offending. Women who are maternal avoidant are also coercive and nonaggressive, but want to avoid offending. It is within this approach that women are often coerced by an abusive male co-offender (Gannon et al., 2008). The aggressive approach, as the name implies, is comprised of women who take an “aggressive stance toward their victim” (Gannon et al., 2008, p. 366). The final approach is the operationalized approach. Sexual assault is used to accomplish certain goals, such as financial gain through sex trafficking (Gannon et al., 2008).

Based on their data, they found that victims respond to the sexual assault in three ways: engaged, submissive, and resistant. Engaged victims “[react] positively to the offense behaviors”; submissive victims “[tend] not to react strongly during the offense, interacting minimally with the offender”; and the resistant victims “[ask] the offender to stop, [cry], or [show] extreme discomfort throughout the sexual offense” (Gannon et al., 2008, p. 366). Post-sexual offense there are offense consequences and offense outcomes. Offense consequences are the offender’s response to the offense, including affective responses like pleasure or shame. They also include cognitive responses, such as thinking about the harm caused to the victim, and behavioral responses, such as avoiding detection and (for some) suicide attempts. Offense outcomes, the final stage in Phase 3, and pertains to how the sexual abuse was resolved (Gannon et al., 2008). Here, women either self-disclosed to the police or are arrested via a police investigation.

While Gannon et al.’s (2008) study detailed the DMFSO itself, follow-up research conducted by Gannon et al. (2014) examined the prevalence of each pathway using the same sample of 22 UK women. They identified nine women as explicit approach offenders, five women as directed avoidant offenders, and four women as implicit disorganized offenders. Due to lack of information, the remaining four women were not assigned a pathway. The DMFSO since has been applied to a sample of North American women with considerable success, although a small minority (six women out of 36) could not be classified into one of the three pathways (Gannon et al., 2014). In addition, some pathways are more easily identifiable, specifically the directed coerced pathway, than the other two pathways, the explicit approach and the implicit disorganized pathway (Gannon et al., 2014).

Overall, the DMFSO is the first temporal model of female-perpetrated sexual abuse and it has had success classifying FSOs based on life course pathways that influence their sexual offending behavior. Based on this and other research that assesses childhood experiences of FSOs, one can see that it is within these early years, childhood and early adolescence, that a variety of cognitive, behavioral, affective, and contextual factors are already influencing women’s trajectory and risk to sexually offend later in adulthood. The DMFSO clearly delineates how these cognitive, behavioral, affective, and contextual factors influence and shape their risk of sexually offending, the sexual assault behavior itself, and outcomes or consequences of their criminal actions post-offense.

Group Composition and Offending Behaviors

As suggested by typology research and the DMFSO, women sexually offend by themselves, but there is ample evidence across various data sources that women co-offend, or have a male accomplice, and that they offend with their male co-perpetrator either by force/coercion or by their own volition (Gannon et al., 2008, 2010, 2014; Mathews et al., 1991; Nathan & Ward, 2002; Williams & Bierie, 2015). While there has long been a recognition of female co-offending, contemporarily researchers also have identified subsets of women who offend in larger groups. This section gives an overview of the different offending dynamics, co-offending pairs and multiple perpetrator groups, and associated characteristics that have been identified in the literature.

Co-Offending

Co-offending, or women who sexually abuse victims with a man, is common among female sexual offenders. According to Williams and Bierie (2015), out of 43,018 sexual assault incidents involving women, approximately 62% involved a solo female sexual offender and about 33% involved a male co-offender. On the other hand, out of the 773,118 sexual assault incidents involving men, approximately 88% of those incidents involved a solo male offender and men co-offended with a woman in only about 2% of the incidents (Williams & Bierie, 2015). Therefore, based on their results, it is evident that women are much more likely to have a male co-offender than it is for a man to have a female co-offender.

Based on the data source, it is impossible to ascertain whether the women were forced by men to take part in the sexual abuse, or if they were willing participants. Qualitative data typically provide the best evidence to distinguish between these two categories of offenders. One of the earliest works distinguishing between these co-offending dynamics was Mathews and colleagues (1991). In their research, male-coerced offenders were forced or coerced by male offenders to sexually fondle their victims, usually their daughters (Mathews et al., 1991). Coercion could take many forms, such as grooming the woman to sexually offend by breaking down sexual norms; here, the woman resists at first but then participates in the sexual assaults (Gannon et al., 2008). Coercion can also take the form of threats and abuse by the male perpetrator (Mathews et al., 1991). The other category of women is male-accompanied (i.e., no coercion to participate) for sexual gratification or due to anger/jealously (Mathews et al., 1991). The male-coerced offender and the male-accompanied offender are still identified in research today. For example, Gannon et al. (2008) found that 50% of their sample offended with a man and that 23% of those women were coerced and 27% were willing participants in the sexual abuse.

To date, five studies have compared solo and co-offending female sexual offenders regarding their offending behavior. Based on this research, there are some overarching patterns in offending behavior based on group dynamics. Some studies indicate co-offenders are more likely to have multiple victims (Vandiver, 2006; Wijkman et al., 2010). As previously highlighted, solo female sexual offenders seem to lack a strong gender preference for their victims (Johansson-Love & Fremouw, 2009). When studies compare solo female sexual offenders to co-offending pairs, findings indicate solo offenders are more likely to choose male victims (Muskens, Bogaerts, van Casteren, & Labrijn, 2011; Vandiver, 2006; Wijkman et al., 2010) and that co-offending pairs are more likely to victimize females (Budd et al., 2017; Vandiver, 2006; Wijkman et al., 2010). This co-offending victim preference may be in part due to male sexual offender’s victim preference—girls (Freeman & Sandler, 2008; Williams & Bierie, 2015). Based on the evidence, co-offending pairs are also more likely than solo female sexual offenders to sexually assault victims that are known to them—dependent children and intrafamilial family members (Budd et al., 2017; Muskens et al., 2011; Vandiver, 2006; Wijkman et al., 2010). This may be partially attibutable to the ability of male offenders to gain access to children and other family members through their female partners. As noted by Gannon et al. (2008, 2010), some females are groomed by their abusive male partners to offend against their own children.

Multiple Perpetrator Groups

Recent studies have reported varying percentages of female sexual offenders who offend within larger groups, and those who extend beyond co-offending. For example, Gannon et al. (2008) found that 23% of the women in their study offended in larger group contexts. A recent investigation of sexual assault incidents by Budd et al. (2017), however, revealed that 9% of the incidents involved women offending in larger group contexts. Examining multiple perpetrator groups, defined as groups of three of more offenders with at least one female, is a newer line of investigation. There is still much to learn about these multiple perpetrator group offending dynamics.

Extant research tells us that within these larger offending groups there is a greater likelihood of stranger victimization, a greater amount of injury to the victim, and more diversity of offending (Budd, 2017; Lambine, 2013; Morgan, Brittain, & Welch, 2012). This means sexual assaults are more likely to occur in conjunction with other crimes, especially robbery (Budd, 2017). As noted by Kelly (2013), women may participate in these group sexual assaults as bids for acceptance and power among men. These larger group offenses may also be a way for women to extract revenge, express jealousy, or get financial rewards (Gannon et al., 2008). Overall, though, more research is needed to better understand these large group sexual assaults not only in terms of offending behavior but also in terms of explanations as to why women participate in multiple perpetrator groups.

Criminal Justice Responses to Female Sexual Offenders

As more attention has been placed on female sexual offenders, scholars have begun to explore possible sentencing discrepancies between female and male sexual offenders. Male and female sexual offenders are subjected to the same laws, such as sentencing schemas for sexual offenses, and are subjected to the same post-conviction and/or post-incarceration social controls. In addition, although public opinion research on sex offender specific legislation has focused on “sex offenders” as whole, a very recent line of research has started to investigate how the public reacts to these laws and their application to female sexual offenders.

Pertaining to criminal justice sanctions , there is evidence that FSOs are significantly more likely to serve their sentence in the community rather than in a correctional institution. For example, Ferguson and Meehan’s (2005) research on convicted FSOs in Florida revealed that 64% of their sample was placed on parole/probation after conviction and 36% were incarcerated. This makes sense in light of prior findings on arrest, convictions, and sentencing: Women compared to men are less likely to get arrested, less likely to be convicted, and more likely to serve shorter sentences than men (Blackwell, Holleran, & Finn, 2008; Rodriguez, Curry, & Lee, 2006; Sarnikar, Sorensen, & Oaxaca, 2007). With that said, in general, criminal justice sanctions are becoming more punitive for individuals convicted of sex crimes, especially regarding the movement to incarcerate and have offenders serve longer sentences (Center for Sex Offender Management, 2001; Cohen & Jeglic, 2007). Indeed, the public seems to support these sentencing changes (Levenson, Brannon, Fortney, & Baker, 2007). One has to question, though, whether there are differences in criminal justice sanctions for male and female sexual offenders given that sex crimes are viewed as one of the most heinous crimes in contemporary society.

In one of the first studies on sentencing disparity , Sandler and Freeman (2011) analyzed conviction and sentencing data from 1986–2005 using a sample of 138,000 offenders arrested for a sexual offense in New York State. To compare male and female sexual offenders and criminal justice sanctions they systematically tracked three different arrest outcomes: conviction for a sexual offense, conviction for a nonsexual offense, and no conviction. In addition, for those convicted, they assessed whether female sexual offenders were given more lenient sentences than their male counterparts. Overall, they found there was no difference between men and women and their likelihood for a sexual conviction (Sandler & Freeman, 2011). But gender did play a significant role in sentencing outcomes. In New York State, female sexual offenders were more likely to be sentenced to conditional release or a fine/unconditional release compared to men who were sentenced to incarceration. Findings by Embry and Lyons (2012) support the hypothesis that female sexual offenders are treated more leniently when adjudicated. Using National Corrections Reporting Data from 1994 to 2004, they found male sexual offenders were more likely to receive longer sentences for sexual offenses than female sexual offenders for specific types of sex crimes: rape, child sexual assault, and forcible sodomy. There were no significant differences for sentencing for sexual assault and statutory rape (Embry & Lyons, 2012).

These studies provide consistent evidence that female sexual offenders seem to be treated more leniently compared to male sexual offenders within the criminal justice system. This appears true even in light of trends that show an increasing use of incarceration and longer sentences for sex crimes. Some researchers posit these lenient patterns may be an extension of the gender-based “chivalry hypothesis,” that women are viewed as less culpable and that they should not be held to the same standards as men (Embry & Lyons, 2012; Sandler & Freeman, 2011). In addition, those in charge of making discretionary sentencing decisions, such as prosecutors and judges, may not view female sexual offenders as an imminent threat given their low recidivism rates (Sandler & Freeman, 2011). Whether these patterns are related to gendered narratives about sexual offending, evidence-based practices in sentencing based on research, or other legal or extralegal factors, remains to be seen.

In short, more research is needed to better understand the nuances of arrests, convictions, and sentencing of female sexual offenders. What other sociodemographic characteristics beyond gender influence arrest, convictions, and sentencing of female sexual offenders? Court actors may also shed light on these discrepancies in sentencing schemas by delineating their use of legal and extralegal factors. In addition, is sentencing female sexual offenders to a term of incarceration decreasing their already low rates of recidivism? Other researchers have assessed sentence length, time served, and recidivism with male sexual offenders (Budd & Desmond, 2014), but this has yet to be investigated with FSOs. Addressing sentencing philosophies that are linked to convicting and sentencing female sexual offenders, such as retribution, incapacitation, or rehabilitation, may also shed light on this phenomenon.

Sex Offender Legislation , Public Perceptions , and Female Sexual Offenders

In addition to convicting and sentencing sexual offenders within the court system, there are other methods of community-based social controls for individuals convicted of sex crimes. Sex offender-specific legislation calls to arm various branches of the criminal justice system, such as police officers, probation officers, and parole officers, to manage convicted sex offenders within communities using legal tools such as sex offender registration and community notification and residence restrictions. Given that research on female sexual offenders as a whole is in its infancy, research that gauges public opinion about female sexual offenders and about the application of sex offender-specific legislation to FSOs is virtually nonexistent. This is troubling given the fact that scholars call for a gender-specific approach to FSOs, which also includes the formation of policy.

In the first study of its kind, Cain et al. (2015) used public opinion data from the 2012 Nebraska Annual Social Indicators Survey to assess whether community members would want to be notified if a female sexual offender moved into their neighborhood. In addition, they inquired whether individuals would take preventative actions against female sexual offenders if these offenders moved into their neighborhood. This study is unique in that while it assesses public perceptions of law and the public’s corresponding protective behaviors, it also brings to the forefront public perceptions about an offending population that has long been denied existence.

Would individuals want to know if an FSO moved into their neighborhood? The majority of the respondents, approximately 91%, said they would want to be notified (Cain et al., 2015). In addition, about 56% of respondents said they would take some type of preventative action if a female sexual offender lived in their neighborhood, although about 27% were not sure if they would take preventative action and about 18% said that they would not take preventative action (Cain et al., 2015). Women and those with minor children living in the home were found to be significantly associated with preventative action. These findings make sense in light of other studies that have gauged public opinion on sex offenders in general: women typically are more supportive of sex offender community protection policies and parents, more so than other groups, are supportive of these laws (Levenson et al., 2007; Mancini, Shields, Mears, & Beaver, 2010).

While the findings from this study should be viewed cautiously, as it only addresses public opinion in one state about FSO crime seriousness, the application of laws to FSOs, and community members’ behaviors towards FSOs, it provides a foundational building block for additional research. Given that research has distinguished differences in offending patterns for male sexual offenders and FSOs, especially the low risk of recidivism for FSOs, researchers should continue to address whether law and public policy pertaining to sexual offenders should be applied in the same way to all groups of sexual offenders. In addition, given the public’s overwhelming support for sex offender legislation, which is argued to be driven by fear and myths about sex offenders (Levenson et al., 2007; Quinn, Forsyth, & Mullen-Quinn, 2004), we have to question whether such studies should be used to inform sex offender public policy. As with male sex offenders , there is a need to uncover what myths and misperceptions may be driving public opinion and public (re)actions toward female sexual offenders.

Conclusion

There is still a cultural resistance to recognizing that women are perpetrators of sexual abuse. While the knowledge we have today, and especially produced within the past 5–10 years, has advanced what we know about female sexual offenders, there is still a lot we do not know. This review has underscored areas that need further advancement, such as the need to continue to understand FSO behavior and the processes that lead up to their sexual offense, the commission of their sexual offense, and their post-offense characteristics. There is a need to better understand FSO group compositions; for example, investigations of FSOs that offend within larger groups composed of men, women, or both. In addition, there is also limited research on criminal justice sanctions for FSOs including public perceptions about females who sexually offend, what drives these perceptions, and the application of public policy to FSOs. Given the burgeoning interest in female sexual offending and a generation of scholars that are researching this social problem, we will continue to see advancements in our understanding of FSOs, their behaviors, and the social and legal responses to this group of offenders.