Classification of robbery-murder

Studies of offender profiling have tested the homology assumption, which postulates that if the characteristics of a crime are similar, then the offender characteristics will also be similar. The purpose of this study was to examine whether there is a relationship between offense type and offender characteristics when robbery-murder is categorized on the basis of criminal behavior, taking into account situational influences. A total of 387 robbery-murder cases that occurred in Japan between 2004 and 2014 were analyzed using multiple correspondence and hierarchical cluster analyses. This analysis identified three types of robbery murders. The first type included “store-targeted” offenders who targeted victims in their 50s and committed crimes at night in stores or taxis. In such cases, the offenders were unknown to the victims, had never been married, and committed the crimes alone. The second type included “home-invasion” offenders who mainly attacked women and people in their 70s or older during the daytime in their residences. Compared to two other types, criminals often dumped or concealed victims’ bodies. In these cases, the offenders were married men who knew the victims. The third type included “street-crime” offenders who committed crimes on the street at night targeting victims in their 20s or 30s. In these cases, the offenders were unknown to the victims, had committed the crimes with an accomplice, had a criminal history, and were younger than the offenders in the other two types with a median age of 29.5 years. Statistically significant associations were found between these typologies and several offender characteristics. Thus, these findings suggest that the homology assumption holds.