Study
Morrow, Katz, and Choate (2016) used a quasi-experimental design to assess the effects of the Phoenix (Ariz.) Police Department’s body-worn cameras on arrest, prosecution, and conviction in intimate-partner violence cases. The Maryvale precinct, selected as the study site, was operationally and geographically divided into two similarly sized squad areas that provided first-response coverage to calls for service on a 24-hour basis, 7 days a week. There generally were between 100 and 110 patrol officers equally divided between these two squad areas. Area 81 served as the comparison group, and Area 82, where officers wore body-worn cameras, served as the target group. Fifty-six camera systems were purchased and deployed in Area 82 on April 15, 2013. Departmental policy involving the use of the cameras was formulated before implementation and was also an integral part of the training by the Phoenix Police Department.
The two areas were geographically similar (Area 81 was 7.4 square miles, and Area 82 was 7.9 square miles) but differed in population size (71,676 individuals in Area 81, compared with 56,630 individuals in Area 82) and percentage of population under age 18 (39.5 percent in Area 81, and 43.1 percent in Area 82). Area 82, the target area, had a larger proportion of Hispanic or Latino residents (82.5 percent, compared with 71.1 percent in Area 81, the comparison area) but fewer Black residents (3.9 percent in the target area, compared with 6.4 percent in the comparison area). Calls-for-service rates in the two areas were not statistically significantly different for violent offenses, property offenses, and overall calls for service. The two areas were also similar for intimate-partner-violence–related calls; in the comparison Area 81, the rate was 2.3 calls per 10,000 residents, compared with 1.9 calls per 10,000 residents in the target Area 82.
Three sources of data were used for the analysis: 1) domestic violence pocket card data, 2) court data, and 3) arrest reports. The domestic violence pocket cards are a specialized form of the Field Interview card, designed specifically for intimate-partner violence incidents, and all Phoenix Police Department officers are required to complete this pocket card for each incident regardless of whether an arrest is made. These data were used to track intimate-partner violence cases in the Maryvale precinct from Jan. 1, 2012, through July 31, 2014, from incident initiation through prosecutorial disposition and sentencing. There were 2,063 incidents during this period. Court processing data from Jan. 1, 2012, through Oct. 31, 2014, were collected from the City of Phoenix Prosecutor’s Office. All police contacts involving intimate-partner violence in the precinct were identified (through the domestic violence pocket cards) and were then tracked through the Prosecutor’s Office case processing system. Incidents from the police were collected through July 31, 2014, but court document searches concluded on Oct. 31, 2014, to allow 90 days for those cases to be concluded. The following were then determined for each incident: whether the incident resulted in an arrest (and would thus be forwarded to the Prosecutor’s Office), whether the case was declined, whether charges were filed, the outcome of the case (dismissal, conviction, sentencing), and the amount of time that it took to process the case from arrest to final disposition or outcome. These data were linked to the assignment of officer-worn body cameras. Analyses were case-based and conducted by comparing the case processing of three groups: 1) pretest intimate-partner violence cases (n = 878); 2) posttest comparison cases (no video file, n = 933); and 3) posttest camera cases (video file available, n = 252).
The analytic strategy relied on precamera and postcamera deployment case outcome data from the target and comparison areas. The study period covered about 30 months: 15 months precamera deployment and 15 months postcamera deployment. Intimate-partner violence case outcomes were compared across the target and comparison groups, and the analyses relied on the presence of a body-worn camera on the officer responding to an incident and its subsequent impact on processing and outcome of the case. The CrimeSolutions review of this study focused on the results comparing posttest cases with a body camera (the target area), and posttest cases without a body camera (the comparison area). No subgroup analysis was conducted.
