2005/06/15 Council Agenda Packet

Consultants' Final Report - Page 19 and theft. None of these rankings is significantly different than the median, of course, and furthermore, the rankings fluctuate slightly from year to year. While Garden Grove has an "average" crime rate relative to other cities, however, like any other city, Garden Grove has a range of "high" and "low" crime neighborhoods. We will address this point in greater detail shortly. For the present, it is important to note that crime rates vary widely across any city. Crime rates also vary widely over time. To illustrate again, Figure 2 shows annual Part I and Part II crime totals for Garden Grove over the decade of this study, 1981-1990.30 In some cases, auto theft and assault, for example, crime appears to trend steadily upward. In other cases, particularly burglary, crime appears to trend steadily downward. In all cases, however, the trend is onh, apparent_ In every constant spatial area that we have examined for this report, we found ten ,year trends to lie well within the bounds of stochastic error. In other words. we found no statistically significant trends. For reasons too numerous, complicated, and obscure to be discussed here, time series of crime totals drift stochastically from year to year and it is the mathematical nature of a drifting process to appear to rise or fall systematicaIIy over time. Although this phenomenon has been widely reported by statisticians since the early 19Lh century, it is not well 30 Since these are crime totals (not crime rates), Figure 2 must be interpreted cautiously. Due to annexation, in -migration, out -migration, and growth, the population of Garden Grove has changed dramatically over the last ten years. EVER00361