Arresting an assailant in a domestic violence case significantly reduces the likelihood of future violence. In the first scientifically controlled test of the effects of arrest for any crime, arrest was found to be the most effective of three standard responses used by police when responding to cases of domestic violence.

Police frequently are called upon to intervene in domestic assaults. But over the years, police mental health professionals, and advocacy groups have differed as to how officers should handle these situations.

The most common police response had been to do as little as possible. The police felt that physical violence within the home was exempt from the laws governing street assaults. Mental health experts agreed that the police should not make arrests. Instead, they suggested that officers use counseling and mediation to prevent further violence.

Others, however, including women’s rights groups, strongly criticized the "no arrest" policy. They encouraged the police to treat domestic assaults as criminal offenses subject to arrest. Some states, including Minnesota, have enacted statutory reforms making arrest possible in misdemeanor domestic assault cases even if officers did not witness the assault.

Because police officers have used hunch, supposition, and tradition as their guides to handling domestic violence, the Police Foundation decided to test empirically their response to domestic violence. The results, it was hoped, would help departments formulate their own policies for handling domestic disputes.

THE EXPERIMENT
From early 1981 through mid-1982, the Police Foundation and the Minneapolis Police Department conducted a field experiment funded through a grant from the National Institute of Justice. It constituted the first scientifically controlled test of the effects of arrest for any crime.
Three traditional police responses were tested:

• arresting an offender;
• asking an offender to leave the scene of the assault; and
• talking to both offender and victim and giving advice.

Officers used a lottery method to determine which of the three responses they would use on each offender. Interviewers then recontacted victims over a six-month period to measure whether the offenders continued to commit domestic assaults, how often they did so, and how serious the assaults were. Official records were also reviewed.

RESULTS
Domestic violence cases disproportionately involved unmarried couples with lower than average education. Most were minority or mixed racial (black male/white female) relationships. Assailants were likely to have had prior run-ins with police.

Regardless of the race, employment status, educational level, or criminal history of the assailants, however, the study showed that arrest was the most effective way to keep them from committing further violence.

As a result of the experiment, the Minneapolis Police Department changed its policy on domestic assaults. Officers are now required to file written reports explaining why they failed to make arrests when it was legally possible to do so. The new policy’s initial impact was to double the number of domestic assault arrests.

IMPLICATIONS
It may be premature to conclude definitely that arrest is always the best police response to domestic violence, or that all suspects should be arrested. Specifically:

• The study involved a relatively small sample of subjects.
• Minneapolis jails most suspects arrested for domestic assault overnight. Arrest may not have the same impact in cities where suspects return home sooner.
• The cultural context of other cities may differ from that of Minneapolis and thus produce different results.
• Follow-up interviews may have created a "surveillance" effect that stopped suspects from committing further violence.
• There were some inconsistencies between results based on official records of crime and those based on interviews with victims.

Experiments underway in several cities will address these questions and determine whether findings can be generalized. In the meantime, they represent the best information available, and can be used by police to justify arrest in cases of domestic violence.

The experiment apparently did more than contribute to scientific knowledge about policing. It also helped change police behavior. If similar results are found in other cities where replications are being conducted, one of the most common forms of violent crimes may be brought under better control.