Effects of domestic violence policies, alcohol taxes and police staffing levels on intimate partner homicide in large US cities

Objective To assess the relationships between intimate partner homicide (IPH) and public policies including police staffing levels in large US cities. Design The research uses a multiple time-series design to examine the effects of statutes aimed at restricting access to firearms for perpetrators of domestic violence, allowing or mandating arrest for violators of domestic violence restraining orders (DVROs), beer excise taxes, and police staffing levels on IPH in 46 of the largest US cities from 1979 to 2003. Both total IPH and IPH committed with a firearm are analysed. Generalised estimating equations using a Poisson distribution are used to regress IPH on the policies and potential confounders. Results State statutes restricting those under DVROs from accessing firearms, and laws allowing the warrantless arrest of DVRO violators, are associated with reductions in total and firearm IPH. Police staffing levels are also negatively associated with total and firearm IPH. There was no evidence that other policies to restrict firearm access to domestic violence offenders or alcohol taxes had a significant impact on IPH. Conclusions Reducing access to firearms for DVRO defendants, increasing police staffing levels and allowing the warrantless arrest of DVRO violators may reduce the city-level risk of IPH. Future research should evaluate factors that may mediate the effects of these laws and increased police staffing levels on IPH to determine whether there are opportunities to increase their protective effects. Further research is needed on firearm law implementation to determine why the other tested laws were not found effective.