Results indicated that the previous authors’ findings of a deterrent effect produced by harsher sanctioning in California failed to withstand critical scrutiny with more complete crime data. Specifically, the current analysis found that crime in California actually began to decline prior to the implementation of the sentencing enhancements of Proposition 8 and that the downward trend in crime rates did not accelerate after Proposition 8 was enacted in 1982. The current analysis also brought up questions regarding the comparability of two control groups with the treatment group used in the previous study. The findings suggest that future research on sentencing policy needs to take into account both the appropriateness of the comparisons made and the choice of data under examination. The analysis involved the addition of even-year crime data to the odd-year crime data analyzed in the 1999 study. Data under analysis included monthly data on Index crimes (homicide, rape, robbery, burglary, and aggravated assault) from California’s nine largest cities for the 12-year time period from 1978 through 1989. According to this analysis, crime declines actually peaked in January 1981 and not in June 1982. Future studies should continue to research the efficacy of deterring crime through variation in sentence severity. Figures, tables, footnotes, references