Multiple-Perpetrator and Solo-Offender Sexual Assaults Between Strangers: Differences and Predictive Variables.

Multiple-perpetrator rape is an under-studied topic, but there has been a recent increase in studies on the differences between multiple-perpetrator sexual offenses and the ones perpetrated by solo offenders. This study aims to have a deeper understanding of the differences between multiple-perpetrator and solo-offender sexual assaults committed by strangers, from a sample of 400 sexual aggressions reported to the Spanish police in 2010. Differences were explored on variables related to characteristics of perpetrators, the assault (approach, control, maintenance, termination, and sexual behavior), and the victims. Data were obtained from police files on sexual assaults committed around the country. Significant differences found were similar to other studies conducted in other countries and proved that multiple perpetrator assaults committed by strangers are a different subtype. Additionally, four predictive variables of multiple-perpetrator rape were identified: older age (OR = 0.943, 95% CI = [0.92, 0.97]), alcohol or drug use (OR = 2.499, 95% CI = [1.50, 4.32]), non-Spanish nationals (OR = 1.980, 95% CI = [1.14, 3.45]), and use of violence to control the victim (OR = 2.465, 95% CI = [1.03, 5.90]). The cultural and leisure characteristics of Spanish society provide facilitating opportunities for multiple-perpetrator rapes and prevention strategies should be urgently addressed.