ABSTRACT
Rates describe the number of crimes per target at risk, during a period of time. A target rate, for example, might be one burglary for every 1,000 households during 2002. Target rates describe the risk the average target has of being involved in a crime during the time period. Vehicle theft rates per 1,000 residents, San Diego County, 2001 https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315060965/14bb2c7a-12e5-4548-b4de-25e2536c2d5b/content/fig1d_C.jpg" xmlns:xlink="https://www.w3.org/1999/xlink"/> Calculating rates can be very helpful in diagnosing a problem. This is illustrated by some analyses undertaken by Nanci Plouffe, Karin Schmerler and Rana Sampson to support a POP project on vehicle thefts in Chula Vista, California. Officers believed that the city's close proximity to the Mexican border exacerbated its vehicle theft problem. The fact that Chula Vista's theft rates, and those of other cities closest to the border, were two to six times higher than ones further north in San Diego County supported this hypothesis (Figure 1). Many vehicles were stolen from parking lots and driven across the border before owners had even discovered the thefts. Analysis had also suggested that pick-up trucks - highly prized in Mexico - were at greater risk of theft in Chula Vista and in the two other cities closest to the border. Figure 2 confirms that the recovery rate of these trucks when stolen in Chula Vista was generally lower than in cities further from the border. Other analyses showed that some lots had much higher theft rates than others and, ultimately, the analysis showed that border-point interventions were less valuable in preventing auto theft than efforts to improve the security of lots.
