A 10-Year Study of the Impact of Intimate Partner Violence Primary Aggressor Laws on Single and Dual Arrest.

The adoption of arrest as the preferred response in incidents of intimate partner violence has generally been welcomed, but it has not come without unintended consequences. Foremost among these has been an increase in dual arrest, the situation where both parties to an incident are arrested. To address this concern, many states have enacted primary aggressor laws which mandate that officers determine who is the primary aggressor in the incident. To date, no longitudinal national study has been conducted on the impact of these laws. Using a dataset comprising 10 years of National Incident Based Reporting System (NIBRS) data (2000-2009) from 5,481 jurisdictions in 36 states and the District of Columbia, the authors examine the impact of primary aggressor laws in reducing the prevalence of dual arrests. Taking into account such factors as seriousness of offense, the authors found that the existence of primary aggressor laws does appear to result in officer reluctance to make any arrest. In addition, though these laws do result in a reduction in dual arrests, this reduction was not statistically significant. This is undoubtedly a result of inter-state variation in implementation as well as variations in statutory framework. In addition, these laws were observed to have a disparate effect both on White and non-White and heterosexual and same-sex couples. The policy implications of these findings are discussed.

The impact of offenders leaving the scene on the police decision to arrest in cases of intimate partner violence.

In this article, the authors examine an issue that has not been studied in depth by prior research: the impact that fleeing the scene has on the likelihood of arrest in intimate partner violence cases. Using police data obtained from 25 police departments in four states, and controlling for a variety of incident, offender, victim, and jurisdictional characteristics, the authors find that an offender who flees the scene of the incident is more than 5 times less likely to be arrested than one who remains at the scene. The policy implications of the findings are discussed.

Severity of injury and the decision to arrest in cases of intimate partner violence.

From a victim's physical health perspective, at the centre of any case of intimate partner violence (IPV) is the degree of trauma imparted on that victim by the offender. Yet, the implementations of state-level 'Mandatory Arrest' and 'Preferred Arrest' laws encourage arrests decisions in cases of IPV typically without regard to the level of trauma severity found in each case. And, despite these well-meaning implementations and the gravity of their consequences, the importance of evaluating trauma severity in victims of IPV remains largely overlooked. The goal of this study was to correlate police arrest decisions in cases of IPV to a trauma severity score generated from established clinical protocols in the treatment of trauma. A Trauma Severity Quantification Table (TSQT) was created in order to quantify the major factors of an incident of IPV: anatomical location of attack, method of attack, facilitating weapon/object and resulting trauma. A total of 256 cases of IPV reported to six police departments in Idaho, a state with a discretionary arrest law in domestic violence cases, in the calendar year 2000 were processed using the TSQT. A statistically significant difference was found between arrests (mean 17.96, standard deviation [SD] 5.90) versus no arrest (mean 16.13, SD 5.67) outcomes (P = 0.03). It is suggested that trauma severity is a factor in police arrest decisions in a discretionary state sample, but that more attention needs to be brought to this method of analysis and its implications for future arrest decisions.

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

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.

A comparison of the police response to heterosexual versus same-sex intimate partner violence.

It has been argued that the police do not respond to domestic calls involving same-sex couples in the same manner as they respond to calls involving heterosexual couples. A major problem facing researchers examining the police response to cases involving same-sex couples has been the lack of adequately sized samples. In this article, the authors utilize the 2000 National Incident Based Reporting System database, which contains 176,488 intimate partner assaults and intimidation incidents reported to 2,819 police departments in 19 states. The key issue examined is whether similar cases involving same-sex and heterosexual couples result in the same police response.