Objectives

Test direct, spillover, and aggregate effects of hot spots policing on crime in a high-crime environment.

Methods

We identified 967 hot spot street segments and randomly assigned 384 to a six-month increase in police patrols. To account for the complications resulting from a large experimental sample in a dense network of streets, we use randomization inference for hypothesis testing. We also use non-experimental streets to test for spillovers onto non-hot spots and examine aggregate effects citywide.

Results

Our results show an improvement in short-term security perceptions and a reduction in car thefts, but no direct effects on other crimes or satisfaction with policing services. We see larger effects in the least secure places, especially for short-term security perceptions, car thefts, and assaults. We find no evidence of crime displacement but rather a decrease in car thefts in nearby hot spots and a decrease in assaults in nearby non-hot spots. We estimate that car thefts decreased citywide by about 11%.

Conclusions

Our study highlights the importance of context when implementing hot spots policing. What seems to work in the USA or even in Bogotá is not as responsive in Medellín (and vice versa). Further research—especially outside the USA—is needed to understand the role of local crime patterns and police capacity on the effectiveness of hot spots policing.

中文翻译：

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高犯罪率环境中的热点警务：麦德林的实验评估

目标

测试热点警​​务在高犯罪率环境中对犯罪的直接、溢出和综合影响。

方法

我们确定了 967 个热点街道段，并将 384 个随机分配给 6 个月增加的警察巡逻。为了解释密集街道网络中大量实验样本导致的并发症，我们使用随机推理进行假设检验。我们还使用非实验街道来测试对非热点地区的溢出效应，并检查全市范围内的总体效应。

结果

我们的结果表明，短期安全意识有所改善，汽车盗窃有所减少，但对其他犯罪或对警务服务的满意度没有直接影响。我们在最不安全的地方看到了更大的影响，特别是对于短期安全感、汽车盗窃和袭击。我们没有发现犯罪转移的证据，而是发现附近热点地区的汽车盗窃减少了，附近非热点地区的袭击事件有所减少。我们估计全市范围内的汽车盗窃案减少了约 11%。

结论

我们的研究强调了在实施热点警务时上下文的重要性。在美国甚至波哥大似乎有效的方法在麦德林没有那么灵敏（反之亦然）。需要进一步研究——尤其是在美国以外——以了解当地犯罪模式和警察能力对热点警务有效性的作用。