Offender-victim body mass ratio and the decision to arrest in cases of intimate partner violence

Abstract

As a result of the growing trend toward criminalisation of cases of domestic violence, there has been a great increase in the number of jurisdictions in the United States that have implemented ‘pro-arrest’ and ‘mandatory arrest’ laws. One of the objectives of this legislation is to encourage arrest when there is probable cause to believe that an assault has occurred. Along with the increase in the overall rate of arrest for intimate partner violence there has been a dramatic increase in the arrest of both the parties involved in an incident. In these cases the police do not identify any one party as the primary aggressor. A number of factors may account for this. Analysing these factors can prove beneficial in guiding protocol design and the arresting officer's decision-making process. A yet untested factor that may help explain police arrest practices concerns the relative body mass between the two parties and whether the police use this factor to determine which party is the primary offender. In this study we examine the basic relationship between offender and victim body masses and arrest decisions in 950 cases from police departments in four states: Connecticut, Idaho, Virginia and Tennessee. Our analysis finds that a significant correlation exists between offenders' and victims' body masses, and the resulting arrest decisions. The cause for this relationship remains unspecified, but may involve several factors such as the ability of a larger offender to inflict trauma on a smaller victim, or simply an arresting officer's perception of offender ability to inflict trauma. The cause of this correlation may have significant implications for arrest protocols in those states currently honouring pro-arrest legislation in cases of domestic violence, and those jurisdictions considering them.