Multiple Perpetrators Research Articles

Identification accuracy of a single culprit in a multiple-perpetrator mock crime

IntroductionEyewitness identification research has mainly examined the identification accuracy of a single perpetrator but many actual crimes involve not one but several perpetrators. ObjectiveThe aim of the study was to examine the identification accuracy if only one lineup for one of the two perpetrators is presented in a multiple perpetrator crime. MethodThe sample consisted of 180 participants who saw a theft video followed by distraction tasks. One group of participants saw lineups for both of the perpetrators (one target present and one target-absent) whereas the other saw only a single lineup (either target-present or target-absent) for one of the two perpetrators. ResultsParticipants who saw a single lineup did not make more inaccurate identification decisions then participants who saw two lineups. Decision accuracy in the first lineup was not associated with the decision accuracy in the second lineup. ConclusionThe results are discussed in terms of the number of perpetrators and line-up presentation types.

Multiple perpetrator sexual assault: correlates of PTSD and depressive symptoms in a sample of adult women

ABSTRACT While most sexual assaults are committed by a sole perpetrator, multiple-perpetrator assaults (MPSAs) still occur. However, less is known about their post-assault impacts. This study examined demographic, assault, and post-assault characteristics as correlates of post-traumatic stress disorder (PTSD) and depressive symptoms in a community sample of adult sexual assault survivors who experienced MPSA (N = 350) in the Chicago area. This study also included demographic and assault characteristics of perpetrators as reported by survivors. Backward regression analysis showed that stressful life events, more violent assaults, post-assault maladaptive coping and characterological self-blame, and receiving acknowledgement without support (e.g. acknowledging the assault happened, but giving inadequate support) reactions were related to greater PTSD symptoms. Older age and greater perceived control over recovery were associated with fewer PTSD symptoms. Greater violence, maladaptive coping, and characterological self-blame were related to greater depressive symptoms, whereas more education and greater perceived control over recovery correlated with fewer depressive symptoms. This study adds to research on MPSA and findings have implications for clinical treatment, intervention, and prevention with survivors.

Multiple perpetrator sexual homicide in Australia and New Zealand: An exploratory study of groups, victims, offenders and offences

PurposeThere is a dearth of research on multiple perpetrator sexual homicide. This is an exploratory and descriptive study of the phenomenon in Australia and New Zealand over the last five decades. MethodCases where sexual homicides were committed by two or more offenders were identified from a legal database. Legal reports and media sources were used to generate case vignettes describing groups, victims, offenders and offences. Summary descriptive data is presented, and the roles of leadership, group composition and sexual sadism are examined. ResultsThere were 23 groups of 62 offenders, who killed 50 victims. Fifteen groups were pairs and eight were three or more. There were some similarities to single perpetrator cases in the literature, but female perpetrators, male victims, multiple victims, ability to form relationships and sadistic behaviour were over-represented. Most groups had a dominant leader. ConclusionLeadership and group effects are key factors in most multiple perpetrator sexual homicides. Current models and typologies of sexual homicide need to be adapted to apply to this phenomenon. Sadistic behaviour in such cases is partly due to sexually sadistic leaders but partly due to the amplifying effect of group dynamics.

Interpersonal Victimization of Latino Youth: a Latent Class Analysis

This study identifies latent classes of interpersonal victimization among Latino youth using a national sample and then compares these latent classes on demographic characteristics, mental health (depression, anxiety, and hostility), and delinquency. We used data from the Dating Violence Among Latino Adolescents (DAVILA) study that surveyed 1525 Latino teens and their caregivers across the USA, by phone, from September 2011 to February 2012. Participants completed modified versions of the Juvenile Victimization Questionnaire and the Conflict Tactics Scales 2- Short Form. Latent class analysis examined victimization types and relationship to perpetrators. We compared latent classes on demographics, mental health, and delinquency via multinomial logistic regression. A six-class solution was found. The six classes were Multiform Victimization by Multiple Perpetrators (n = 184, 12.1%), Psychological Dating Violence Victimization (n = 99, 6.5%), Psychological Victimization by Peers (n = 236, 15.5%), Physical Victimization by Peers (n = 127, 8.3%), Physical Violence Victimization by Juvenile Family Members (n = 93, 6.1%) and Uninvolved (n = 786; 51.5%). Classes differed on some demographic variables, hostility scores, and the rate of delinquency. Our findings provide further evidence regarding the heterogeneity of victimization experiences among Latino youth. LCA results also suggest that victimization occurs across a range of perpetrators, both inside and outside of the home. Hostility and delinquency were central to differentiating the classes, indicating their relevance among poly-victimized Latino youth. This analysis provides further understanding of the various ways Latino youth experience victimization and what factors may differentiate the various groupings of victimization profiles.

A coding tool and abuse data for female asylum seekers.

With 1 in 3 women affected, accounting for one billion women worldwide, Violence Against Women (VAW) constitutes one of the widest reaching human rights violations globally. Although the forms they take may vary, these abuses are not confined to a single social class, geographic region, or culture. Existing studies have yet to describe the full burden of abuse that asylum-seeking women endure throughout their lifetimes. We describe a novel coding tool that classifies types of abuse, identifies abuse perpetrators, and estimates how long and how often each abuse was experienced. The authors used this tool to describe and categorize the abuses endured by 85 cisgender, adult women seeking asylum in the United States who presented to the Weill Cornell Center for Human Rights for forensic medical evaluations from 2013 to 2017. We reviewed a total of 180 legal and forensic medical affidavits that were written in support of the applicants’ asylum claims. Using the coding tool, we identified each abuse, classified every perpetrator, and, whenever possible, estimated how long and how frequently each abuse was endured. Interpretations of the raw data contained in this article and a discussion of their significance can be found in our associated publication: “Gender-Based Violence experienced by Women Seeking Asylum in the United State: A Lifetime of Multiple Traumas Inflicted by Multiple Perpetrators” [1]. The coding instrument described herein characterizes VAW by classifying the narrative data that are included in interviews, focus groups, medical records, and the like. Our coding instrument is the first of its kind to describe all types and severities of violence endured by women, classify the perpetrators of that violence, and delineate the timeline of violence over each individual's life. We hope that this holistic approach to classifying and describing VAW will enable other research groups to examine untested or unrealized associations between victims, perpetrators, and abuses. Ultimately, obtaining more complete data will empower us to advocate more effectively and to design more comprehensive care for victims of VAW.

Offence characteristics: a comparison of lone, duo, and 3+ perpetrator robbery offences

ABSTRACT The current study investigated characteristics of robbery offences with a focus on lone versus multiple perpetrator crimes. The main aim was to outline differences between lone, duo, and 3+ perpetrator crimes. Police recorded crime data from West Midlands Police relating to 1574 personal robberies (including attempts) committed in Birmingham city centre (UK) were used in the analysis. Robbery offences were compared on victim and offender demographics and offence characteristics. The findings showed significant differences between the three group sizes (lone, duo, 3+ offenders) in victim and offender age; approach styles; victim control variables; weapon use; alcohol and violence; injuries; and carjacking. The findings of the current research can feed into developing policing strategies which take into account differences in group size.

Violence against women before and during gestation: differences in prevalence rates and perpetrators

Abstract Objectives: to analyze differences in prevalence and perpetrators of violence against women before and during pregnancy. Methods: this is a cross-sectional study with a sample of 1,446 pregnant women interviewed in 2010 and 2011 in the São Luís municipality (Brazil). Thirteen questions measured psychological, physical and sexual violence in the 12 months before and during pregnancy. Psychological/physical/sexual violence was defined as any type of violence perpetrated against the interviewees. The perpetrators were categorized into intimate partner, other family members, community members, and multiple perpetrators. Differences between violence before and during pregnancy were analyzed by the chi-square test. Results: psychological/physical/sexual and psychological violence were more prevalent during pregnancy than before gestation (p<0.001). Insults, humiliation and intimidation (p<0.05) were more frequently reported during pregnancy. An intimate partner was the most frequent perpetrator. There were no differences in the percentage of moderate and severe forms of physical violence and sexual violence, recurrence of aggressions and perpetrators in both periods (p>0.05). Conclusions: gestation did not protect users of prenatal services in São Luís municipality from psychological, physical and sexual violence. Psychological/physical/sexual and psychological violence were more commonly practiced during pregnancy. The perpetrators of violence in the year before gestation continued to abuse the interviewees during pregnancy

Gender-based violence experienced by women seeking asylum in the United State: A lifetime of multiple traumas inflicted by multiple perpetrators

Estimates by the World Health Organization indicate that 1 in 3 women—more than one billion people worldwide—have experienced some form of Gender-Based Violence (GBV). Violence Against Women (VAW) is a prominent subset of GBV, defined by the United Nations as any act “that results in, or is likely to result in, physical, sexual, or mental harm or suffering to women, including threats of such acts, coercion or arbitrary deprivation of liberty, whether occurring in public or in private life.” VAW can include verbal harassment, physical abuse, sexual abuse, honor killing, and femicide and can occur at the hands of individuals, institutions, or states. Whereas numerous studies have documented the multiple forms of physical, sexual, and psychological violence experienced by women, a thorough characterization of the abuses experienced by asylum-seeking women in the United States has not yet been undertaken. Our analysis of the affidavits for 85 cisgender, female asylum seekers who applied for forensic medical evaluations through a student-run asylum clinic, reveals a life-long pattern of multiple types of VAW inflicted by multiple perpetrators. These findings have implications for the focus of the medico-legal documentation submitted in support of female asylum seekers as well as for the design of comprehensive healthcare services for women and girls who are granted relief.

Does the number of perpetrators matter? An extension and re‐analysis of workplace bullying as a risk factor for exclusion from working life

AbstractBased on a nationally representative sample (N = 1,613) and a true prospective design, we show that the link between self‐labelled workplace bullying and exclusion from working life (i.e., becoming a non‐participant in working life) over a 5‐year time lag becomes stronger with increasing numbers of perpetrators involved. The amount of exposure to bullying behaviours could not explain the added effect of multiple perpetrators, indicating that the presence of multiple perpetrators is significant in and of itself. A post hoc descriptive cross‐tabulation analysis also showed that when one or two perpetrators were involved at T1, the rate of exclusion from working life 5 years later did not differ substantially from the normal population's exclusion rate. When three or more perpetrators were involved, on the other hand, the exclusion rate approached 50%, indicating that ≥3 perpetrators could denote a critical cut‐off point for a distinguishable group‐bullying phenomenon, at least with respect to exclusion from working life.

Multiple perpetrator rape: Is perpetrator violence the result of victim resistance, deindividuation, or leader–follower dynamics?

Objective: Violence perpetrated by groups has been proposed to result from processes that include deindividuation, instrumental responses to victim resistance, and leader-follower dynamics. Here we compare the explanatory merit of these accounts by analyzing the sequential patterns of behaviors that occurred in 71 accounts of multiple perpetrator rape by 189 suspects against lone females. Method: Victim accounts of the offenses made to the police were coded for leader, follower, and victim actions using the interpersonal circumplex quadrants, and the offenses were rated as involving high or low nonsexual aggression. Results: Analysis of the temporal proximities among victim and suspect behaviors found that (a) in contrast to deindividuation, hostility decreased rather than increased with group size, (b) victim behavior had no significant effect on perpetrator violence, and (c) leader behavior had a significant effect on group violence. Conclusions: Compared with low aggression offenses, high aggression offenses were characterized by the leaders' hostile behaviors reinforcing the hostile behavior of followers, as well as there being some mutual reinforcement from follower(s) to leader. This has implications for theories of (sexual) violence perpetrated by multiple individuals, as well as for clinical work with such offenders. For example, the influence of peers in these offenses has implications for the planning of interventions with such offenders and the sorts of intervention that are likely to be successful.

The demographics of patients presenting for sexual assault to US emergency departments

BackgroundFew studies address the demographics/epidemiology of patients presenting to emergency departments (ED) for evaluation of sexual assault across an entire nation. It was the purpose of this study to analyze the demographics of sexual assault using a national data base. MethodsThis was a retrospective study of prospectively collected data from National Electronic Injury Surveillance System - All Injury Program for years 2005–2013. Patients presenting for sexual assault were analyzed. Descriptive and logistic regression statistical analyses were performed with SUDAAN 11.0.01™ software. A p < 0.05 was considered statistically significant. ResultsSexual assault accounted for an estimated 657,719 ED visits (0.24% of all injuries, and 3.4% of injuries due to violence). When an assault victim presented to the ED, a sexual assault was most likely when the patient was 0–14 years old (OR = 19.48 [12.02, 31.57]), White (OR = 2.12 [1.30, 3.47]), the perpetrator being a stranger (OR = 10.51 [8.21, 13.46]), and occurring at home (OR = 10.05 [6.61, 15.27]). The average annual incidence of ED visits for sexual assault per 10,000 US population was 2.39; 0.47 for males and 4.92 for females. The average was 19.6 years; 90.3% were female. Assaults occurred in the home in 45.6%, and were more common in the summer. The perpetrator was unknown in 37.5%, a friend/acquaintance in 24.8%, other relative in 9.4%, multiple perpetrators in 9.3%, spouse/partner in 6.8%, with the remaining 12.7% from other groups. Racial composition was White in 60.9%, Black in 25.9%, Amerindian in 12.5%, and Asian in 0.5%. The perpetrator was a close relative nearly twice as frequently for male victims compared to female victims. Hospital admission overall was 2.7%: 7.1% when the assault occurred on the street, 1.8% when at school or sporting locations, 4.9% for males and 1.5% for females. Nearly all (98.2%) extremity injuries occurred in females. ConclusionsSexual assaults account for 4.4% of ED visits for violence. There was a decrease in the number of sexual assaults occurring on the street and at school/sporting locations over time while the number of assaults by strangers increased. For males, 54.1% occurred in those <10 years of age. The differences between patients by demographic and event characteristics is important information for health care providers.

Associations Between Violence and HIV Risk Behaviors Differ by Perpetrator Among Russian Sex Workers.

Violence is associated with HIV and HIV risk behaviors among female sex workers (FSW). However, few studies assess multiple forms of violence and multiple HIV risk behaviors to build a comprehensive picture of how violence is implicated in HIV risk. Using respondent-driven sampling, 754 FSW were recruited in the Russian Federation. Surveys collected data on lifetime exposure to client, police, intimate partner, and pimp violence, as well as recent HIV risk behavior in the forms of injecting drug use (IDU), and inconsistent condom use with intimate partners and clients. Multivariable log-binomial and Poisson regression were used to assess associations between violence and HIV risk behavior outcomes. Lifetime client (31.7%), police (16.0%), intimate partner (15.7%), and pimp (11.4%) violence were prevalent. IDU (10.7%) and inconsistent condom use with intimate partners (45.1%) and clients (22.5%) were common. Intimate partner violence (IPV) and client violence were associated with IDU (ARRIPV 2.12, 95% CI 1.10, 4.10; ARRClient 2.75, 95% CI 1.19, 6.32), IPV and police violence were associated with inconsistent condom use with intimate partners (ARRIPV 1.10, 95% CI 1.01, 1.19; ARRPolice 1.11, 95% CI 1.01, 1.21), and IPV and police violence were associated with inconsistent condom use with clients (ARRIPV 1.49, 95% CI 1.02, 2.17; ARRPolice 1.65, 95% CI 1.19, 2.29). Each perpetrator-specifictype of violence was associated with a unique set of HIV risk behaviors. Comprehensive violence prevention programming that addresses multiple perpetrators of violence against FSW, including clients, intimate partners and police, is critical for reducing sexual and drug-related HIV risk in FSW.

The Nature of Child Sexual Abuse among Boys and Girls Attending Saint Mary's Sexual Assault Referral Centre in Greater Manchester

This study set out to answer the research question: ‘What are the similarities and differences in the nature of abuse, patterns of disclosure and characteristics of the perpetrator between boys and girls attending a sexual assault referral centre (SARC) for a forensic medical examination?' Retrospective data collection was undertaken from paper case files of 986 service users (142 boys, 844 girls) who attended Saint Mary's SARC for a forensic medical examination (April 2012–March 2015). Demographic data as well as information on the context of the abuse were coded into a standardised digital format. Cross‐tabulation and Pearson's chi‐squared tests were performed to compare the abuse experienced and how abuse was disclosed by children of different genders and ages. Older children accounted for 20 per cent of the boys and 56 per cent of the girls. A higher proportion of girls attended the SARC after a single abusive episode; the abuse of boys was more frequently reported by a parental figure; and boys' abuse was reported later. Younger children were more likely to be abused in the family environment. Younger girls were more likely to experience abuse by a single perpetrator, whereas all boys reported multiple perpetrators. These findings suggest that the relationship between child sexual abuse (CSA) and gender is a complicated and nuanced one.‘What are the similarities and differences in the nature of abuse, patterns of disclosure and characteristics of the perpetrator between boys and girls attending a sexual assault referral centre (SARC) for a forensic medical examination?'Key Practitioner Messages Some gender differences in CSA may be due to professionals' perceptions. It is important to remain mindful that boys may present differently to girls. Care should be taken when interpreting these results. The majority of CSA is not disclosed nor identified. Where it is, few children receive a forensic medical examination. Practitioners need to be alert to this to safeguard children adequately. Future research can pursue how identified differences affect boys and girls, thereby enabling better support or protection for children.

Introduction to the special issue on multiple perpetrator sexual offending

The term multiple perpetrator rape (MPR) was proposed by Horvath and Kelly (2009, p. 94) as an overarching term when referring to a “sexual assault which involves two or more perpetrators”. Althoug...

Supplemental Material for Multiple Perpetrator Rape: Is Perpetrator Violence the Result of Victim Resistance, Deindividuation, or Leader–Follower Dynamics?

Supplemental Material for Multiple Perpetrator Rape: Is Perpetrator Violence the Result of Victim Resistance, Deindividuation, or Leader–Follower Dynamics?

Participative leadership and hierarchical structures in multiple perpetrator rape: replicating and extending a scale of influence among offenders

ABSTRACTThis paper replicates and extends Porter and Alison’s (2001. A partially ordered scale of influence in violent group behavior: An example from gang rape. Small Group Research, 32(4), 475–497) method of leader identification in Multiple Perpetrator Rape (MPR). The study examined 216 MPR offences (totalling 712 different offenders), collected from archival sources (predominantly law reports). Porter and Alison’s original coding scheme was refined and Multidimensional Scaling identified a partially ordered scale of influence based upon the decisions, actions and orders made by the offenders at each chronological offence stage. The updated scale identified leaders in 97% of the sample groups. The hierarchical structures of the groups were also examined through the distribution of influence among co-offenders. While the majority (68%) of cases exhibited a dichotomous leader/follower structure, some “followers” also exhibited influence tactics to varying degrees with the presence of “lieutenants” and linear hierarchies. The findings are discussed in relation to group dynamics as well as the reliability and validity of the influence scale.

ARTICLE: A Statistical Analysis of Predictors Associated with the Dramatic Decline in Death Sentences in the United States in the Last Two Decades

The annual number of new death sentences in the United States has fallen by more than 75% in the last two decades. The current study examines 1,665 death-eligible cases from 1994, 2004, and 2014 to draw empirically based conclusions that can shed light on some significant predictors associated with this dramatic decline. The results of logistic regression models suggest that the following were consistently significant predictors of case outcomes throughout the country over time: multiple perpetrators, age of perpetrators between 18 and 20 years, number of mitigators, cases with high and low aggravation, and five formerly high-volume counties. By contrast, factors that were important predictors of case outcomes in 1994 but that became insignificant in later years were robbery-murder and limited-revenue counties; the murder rate was not significant in 1994 but became significant in later years. Allegations of intellectual disability and county population size were not significant predictors in any of the years.

Insomnia symptom trajectories among adult survivors of childhood sexual abuse: A longitudinal study.

Childhood sexual abuse (CSA) is associated with sleep disturbances in adulthood. However, longitudinal studies have yet to identify among CSA-survivors subgroups distinguished by the trajectory of their insomnia severity, or predictors of subgroup membership. The objective of this study was to examine longitudinal insomnia symptom trajectories, as well as predictors and correlates of the identified trajectories, over a 4 year study period in a sample of adult, mainly female CSA-survivors. The sample comprised 533 adult survivors of CSA (94.9% women, mean age 39.2 years, mean age of abuse onset 6.5 years), recruited from support centers for sexual abuse survivors in Norway. Latent class growth analyses were used to identify insomnia symptom trajectories. Three distinct trajectories of insomnia symptoms were identified; one characterized by high insomnia symptom scores minimally decreasing over the study period ('high and decreasing', 30.6%), one characterized by stable intermediate insomnia symptom scores ('intermediate and stable', 41.5%), and one characterized by stable low insomnia symptom scores ('low and stable', 27.9%). Predictors of belonging to the high and decreasing trajectory (using the low and stable trajectory as a reference), was lower age of abuse onset (expotentiated coefficient (EC): 0.93, p = 0.026), abuse involving penetration (EC: 2.36, p = 0.005), threats (EC: 3.06, p < 0.001) or physical violence (EC: 3.29 p < 0.001), a higher score on a composite variable comprising multiple other abuse and perpetrator aspects (EC: 2.55, p < 0.001), as well as scoring above a clinical cut-off on a measure of posttraumatic stress symptoms (EC: 12.17, p < 0.001). Those belonging to the high and decreasing trajectory also reported lower levels of perceived social support and higher levels of subjectively experienced relational difficulties compared to those belonging to the two other trajectories. We conclude that different longitudinal insomnia trajectories exist among adult CSA survivors. The overall results, as well as the significant predictors, are discussed alongside their potential clinical implications.

Examining the role of pornography and rape supportive cognitions in lone and multiple perpetrator rape proclivity

ABSTRACTSince a substantial proportion of sexual offenders are not apprehended, researchers have introduced methods to test the propensity to sexually offend among the general public. Proclivity measures assess self-reported sexual interest in lone and multiple perpetrator sexual offending or rape (MPR), and can examine students and community members who indicate a proclivity to sexually offend. This study examines the role of pornography use and rape supportive cognitions to influence proclivity. Anonymous online data was collected from 295 male university students to assess the role of rape supportive cognitions and pornography use in predicting lone and MPR proclivity. Only rape supportive cognitions predicted scores on lone and MPR proclivity measures.

Eyewitness identification procedures for multiple perpetrator crimes: a survey of police in Sweden, Belgium, and the Netherlands

ABSTRACTA considerable proportion of crimes involve multiple perpetrators. Yet, little is known about how police officers construct, administer, and record eyewitness identification procedures for multiple suspects. An online survey of law enforcement agents in Sweden, Belgium, and the Netherlands (N = 51) was conducted to obtain an initial understanding of police perceptions of prevalence and characteristics of multiple perpetrator crimes, and to examine identification procedure practices given the little to no guidance provided for police. Practice converged when it came to the use of sequential, photographic lineups, but diverged between and within countries on whether or not suspects of multiple perpetrator crimes should be placed in separate lineups. Results specifically highlight contextual cuing as one critical area for future research in identification for multiple perpetrator crimes (i.e. placing multiple suspects in the same lineup or asking eyewitnesses to look for a specific suspect).