NCJ Number
168461
Journal
Crime and Delinquency Volume: 43 Issue: 4 Dated: (October 1997) Pages: 457-469
Date Published
1997
Length
13 pages
Annotation
Using monthly data drawn from the 10 largest cities in California and an interrupted time-series design with nonequivalent dependent variables, this study assessed the impact of California's "three strikes and you're out" law on the serious crime rate and on a control series measured as the petty theft rate.
Abstract
For each city, time-series data for the 1985-95 period were obtained from the California Department of Justice, Uniform Crime Reporting Program. These data include monthly tabulations of offenses known to police. Two dependent variables were used in this analysis. The first, the serious crime rate, was measured as the number of reported index crimes divided by the city population and multiplied by 100,000. The second dependent variable, the petty theft rate, was measured as the number of reported misdemeanor larcenies (thefts less than $50) divided by the city population and multiplied by 100,000. This measure is referred to as the California Crime Index (CCI), which is used by the California Department of Justice. The overall means for the CCI and petty theft rates during the preintervention period were 397.2 and 123.1, respectively. After the enactment of the law, the CCI rate dropped by 15 percent, and the petty theft rate declined by 7 percent. These reductions are statistically significant at the .01 level of analysis. Although these results appear to support the position that the three-strikes law reduced both serious and petty theft crime in California, it is important to recognize that simple comparisons of preintervention and postintervention means are only suggestive. Further evidence is needed before accepting these findings as definitive, because it is not possible to say whether the observed decrease in crime levels was due to the three-strikes law or whether it was the result of a pre-existing downward trend. 2 figures, 1 table, 9 notes, and 14 references