After mandatory arrest policies were enacted, arrest rates in IPV cases increased, but this has not been universally viewed as beneficial because it has included an increase in dual arrest, and in the arrest of women/victims.

After “mandatory and preferred arrest” laws and policies were enacted in the U.S., arrest rates in intimate partner violence cases increased considerably and studies have found that states with mandatory arrest laws have higher rates of arrest than states with either presumptive or discretionary warrantless arrest requirements. In the l970s and l980s, rates were generally in the 7% to 15% range; after passage of mandatory arrest laws, rates increased to 30%; and more recently rates have hovered around 50%. This increase in the arrest rate has not, however, been universally viewed as beneficial because it has included an increase in dual arrest, and in the arrest of women/victims. To lessen the likelihood that victims are unjustly arrested, states have also passed “primary aggressor laws” to ensure that police officers identify the “real” offender and arrest only that party. The first state to enact a primary aggressor law was Washington State in 1985; currently, 35 states have primary aggressor laws.

This study included an analysis of 10 years of NIBRS data from 36 states. Its primary finding was that primary aggressor statutes do appear to reduce the number of dual arrests as a percentage of overall arrests. On the negative side, however, the overall percentage of police citizen encounters that result in any arrest declines. Specifically, as an aggregate across all states, there was a 24.8% reduction in the rate of arrests in states with primary aggressor laws compared with states without such a provision.