Objectives

Longitudinal studies from the criminology of place suggest crime hot spots are repeatedly found in the same locations within cities over extended periods of time. Program evaluations of hot spots policing interventions often use much shorter temporal windows to define hot spots. This study examines if stability of patterns is still found when using short and intermediate periods of time to measure crime hot spots.

Methods

We examined 765,235 total crime incidents reported to the Cincinnati Police Department from 1997 to 2016. These incidents were geocoded to 13,189 street segments. We created measures of crime hot spots based on varying temporal periods using three different strategies: pooled observations, group-based trajectory modeling, and k-means clustering. These measures were compared using techniques associated with survival analyses to determine the influence of temporal specification on the retrospective identification of crime hot spots.

Results

Our findings suggest regardless of the temporal specification, most street segments identified as crime hot spots remained crime hot spots across the observed follow-up periods. There was still much variability in patterns based upon temporal specifications and the use of additional years of incident report data did not uniformly provide an improved understanding of which street segments remained crime hot spots.

Conclusions

Program evaluations of hot spots policing strategies do not need to use extended periods of time to observe stability in crime hot spots. The criminology of place should provide more attention to the topic of temporal specification and continue exploring the utility of crime hot spots.

中文翻译：

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时间规范对程序评估犯罪热点的识别的影响：犯罪模式纵向稳定性的检验

目标

来自地方犯罪学的纵向研究表明，犯罪热点在很长一段时间内都在城市的同一地点反复出现。热点警务干预措施的程序评估通常使用更短的时间窗口来定义热点。这项研究调查了在使用短时间和中间时间来测量犯罪热点时，是否仍能找到模式的稳定性。

方法

我们调查了1997年至2016年间向辛辛那提警察局报告的765,235起犯罪事件。这些事件被地理编码为13,189个路段。我们使用三种不同的策略根据不同的时间段创建了犯罪热点的度量：合并观测，基于组的轨迹建模和k均值聚类。使用与生存分析相关的技术对这些措施进行了比较，以确定时间规格对犯罪热点的回顾性识别的影响。

结果

我们的发现表明，无论时间规格如何，在整个观察期间内，大多数被确定为犯罪热点的街道段仍然是犯罪热点。根据时间规格，模式仍然存在很大差异，使用额外年份的事件报告数据并不能始终如一地更好地理解哪些街段仍然是犯罪热点。

结论

热点警务策略的计划评估不需要使用较长的时间来观察犯罪热点的稳定性。场所犯罪学应更多地关注时间指定的主题，并继续探索犯罪热点的效用。