EVALUATING THE EFFECTIVENESS OF ONE-OFFICER VERSUS TWOOFFICER PATROL UNITS

• NCJ Number: 67148
• Author(s): E H KAPLAN
• Date Published: January 1979
• Length: 31 pages
• Agencies: NIJ-Sponsored

Annotation

THIS ARTICLE PRESENTS A MODEL-BASED EVALUATION OF ONEVERSUS TWO-OFFICER PATROL CAR; THE PROS AND CONS OF EACH STRATEGY ARE DISCUSSED, AND PERFORMANCE MEASURES ARE MODELED AND ANALYZED FOR BOTH STAFFING STRATEGIES.

Abstract

FOR A GIVEN MANPOWER LEVEL, ONE-OFFICER PATROLS FIELD TWICE AS MANY CARS AS THE TWO-OFFICER AND INCREASE POLICE VISIBILITY, PREVENTIVE PATROL TIME, AND THE AREA COVERED BY PATROLS. HOWEVER, TWO-MAN PATROLS ARE SAFER FOR POLICE, COST LESS (SINCE THEY REQUIRE HALF AS MANY CARS), AND PROVIDE BETTER-QUALITY SERVICE, SINCE MANY SERVICE CALLS REQUIRE AT LEAST TWO OFFICERS. FROM THESE ARGUEMENT, ONE MAY ELICIT RELEVANT PERFORMANCE MEASURES FOR COMPARATIVE ANALYSIS. THESE INCLUDE EXPECTED AREA COVERED BY PATROL, RESPONSE TIME FROM THE NEAREST VEHICLE TO A RANDOMLY OCCURRING INCIDENT, EXPECTED FREQENCY OF PATROL, VISIBILITY OF PATROL, PROBABILITY OF INTERCEPTING A RANDOMLY OCCURRING CRIME IN PROGRESS, PROBABILITY OF OFFICER INJURY, AND COMPARATIVE COSTS. SIMPLE PROBABILISTIC MODELS ARE USED TO COMPARE THE TWO STAFFING STRATEGIES ON THESE PERFORMANCE MEASURES, AS WELL AS EXPERIMENTAL DATA FROM A SAN DIEGO, CALIF., STUDY ON PATROL. RESULTS SHOW THAT DOUBLING THE NUMBER OF AVAILABLE UNITS IN A BEAT DOES NOT DOUBLE THE COVERAGE CONCENTRATION, AND COVERAGE INCREASES ARE MOST SIGNIFICANT IN LARGE BEATS. ALTHOUGH ONE-MAN UNITS MAY REDUCE RESPONSE TIME CONSIDERABLE SINCE MORE UNITS ARE AVAILABLE, INCREASES IN POLICE VISIBILITY ARE LIKELY TO SET IN ONLY AFTER SOME CRITICAL LEVEL OF ONE-UNIT PARTOL HAS BEEN REACHED. INCREASES IN CRIME INTERCEPTION DUE TO SWITCHING FROM TWO-MAN TO ONE-MAN UNITS IS MOST SIGNIFICANT IN BEATS WITH HEAVY WORKLOADS. IN AT LEAST ONE CITY, RISK OF INJURY IS EQUIVALENT FOR OFFICERS IN ONE- AND TWO-MAN UNITS. FINALLY, ADDITIONAL COST DUE TO SWITCHING FROM TWO- TO ONE-MAN UNITS IS, IN SAN DIEGO, $2.51 PER HOUR PER UNIT. THUS, MAXIMUM USE OF ONE-MAN UNITS IS FAVORED. IMPLICATIONS FOR FURTHER RESEARCH, AN APPENDIX, CHARTS, TABLES, AND MUCH MATHEMATICS ARE INCLUDED. (PAP)