The helicopter was initially flown on patrol for 12 days and then grounded because of cost limitations. This arrangement was conducive to an interrupted time-series evaluation design with burglary measures taken before intervention, during intervention, and after intervention. Data indicated a decrease in burglaries from baseline to the helicopter-patrol period and an increase in home burglaries from the helicopter period to the postpatrol period. This finding prompted an additional evaluation step designed to strengthen the initial evaluation design. The procedure was replicated for an additional 12 days. This permitted an analysis of the helicopter during five conditions: prior to initial patrol (baseline), during first patrol (first intervention), after the first patrol (second baseline), during the second helicopter patrol (second intervention), and after the second intervention (third baseline). The burglary deterrence effects of the helicopter patrol were replicated in the second intervention. To estimate the cost-benefit comparisons between helicopter patrol and nonhelicopter patrol, the total amount of property loss resulting from burglaries was added to the marginal costs of the helicopter patrol. A positive cost-benefit ratio was shown in two high-density population target are as, while cost-benefits were negative in two low-density areas. Tabular and graphic data are provided, along with a bibliography of nine listings.