Boydstun, J. (1975). The San Diego field interrogation experiment. Washington, DC: Police Foundation.
Location in the Matrix; Methodological Rigor; Outcome:
Neighborhoods, General, Proactive; Moderately Rigorous; Effective
What police practice or strategy was examined?
The study examined the impact of field interrogations (FI) in San Diego, in which police officers proactively stopped, questioned, and sometimes searched a citizen because the officer had reasonable suspicion that the subject may have committed or will commit a crime. Specifically, the major effects of three alternative departmental policies for conducting Field Interrogations were compared: (1) traditional FI practices conducted by patrol officers who have been routinely given extensive training in recognizing valid FI situations and in conducting the interrogations; (2) FI with patrol officers given special additional training to help minimize potential friction between the department and the public; and (3) suspension of all FI activities.
How was the intervention evaluated?
Three patrol areas that were closely matched in terms of their demographic and socioeconomic compositions were selected with one of the strategies implemented in each. Outcome measures included reported crimes considered as suppressible by the San Diego Police Department (i.e., robbery, burglary, and theft) and total arrest rates. The study examined changes within and across study areas between the 7-month pre-test period, the 9-month test period, and the 5-month post-test period.
What were the key findings?
Some level of FI activity, as opposed to none, provided a deterrent effect on suppressible crimes in localized areas. The suspension of FI in the no-FI area was associated with a significant increase in the frequency of total suppressible crimes, and the resumption of FI in this area was associated with a significant decrease in crime. The monthly frequencies of total arrests in the study areas were not significantly influenced by the levels of FI activities.
What were the implications for law enforcement?
The author suggests that the two principal benefits of FIs are their probable deterrent effect on crimes and their contribution to arrests. Potentially, the benefit of FIs might be expanded by increasing the use of FI data by investigators.
Where can I find more information about this intervention, similar types of intervention, or related studies?