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Randomized-Trial Evaluation of a Law Enforcement Application for Smartphones and Laptops that Uses GIS and Location-Based Services' to Pinpoint Persons-of-Interest

NCJ Number
Date Published
January 2014
96 pages

This report summarizes the features and findings of a project that developed, implemented, and evaluated a GIS (geographic information system) smartphone app that identifies the location of persons of interest, such as gang members, sex offenders, and parolees.


In addition to providing information to smartphones, the app (P3i) provides location data to officers' tablets and mobile display terminal laptops. Evaluation of the usefulness of the P3i in the field by 75 officers in the Lincoln Police Department (Nebraska) provided evidence that officers who used the P3i were more productive than the 15 control officers who did not have the P3i. Productivity measures included citation arrests, warrant arrests, and information reports. The researchers caution, however, that factors other than the use of the app could also affect officer productivity. The 75 officers were surveyed regarding the duration, frequency, and intensity of their use of the P3i. In a focus group of a subset of the officers, they expressed enthusiasm for the P3i application as well as their use of new mobile technologies in general. Most of the officers in the focus group used P3i to search for both broadcasts and warrants. The officers had many suggestions for improving the app, including having an iPad that acts as a mobile terminal device in their car. A cost-benefit analysis indicated that implementation of the P3i results in savings of approximately $800 per officer, assuming a 5-year life and 7 percent interest rate. 13 tables, 4 figures, 108 references, and appended P3i survey and the focus group instrument

Date Published: January 1, 2014