Objectives

Gangs are thought to enhance participation in violence. It is expected then that gang-related violent crimes trigger additional crimes in a contagious manner, above and beyond what is typical for non-gang violent crime.

Methods

This paper uses a multivariate self-exciting point process model to estimate the extent of contagious spread of violent crime for both gang-related and non-gang aggravated assaults and homicides in recent data from Los Angeles. The degree of contagious cross-triggering between gang-related and non-gang violent crime is also estimated.

Results

Gang-related violence triggers twice as many offspring events as non-gang violence and there is little or no cross-triggering. Gang-related offspring events are significantly more lethal than non-gang offspring events, but no more lethal than non-contagious background gang crimes.

Conclusions

Contagious spread of gang-related violent crime is different from contagion in non-gang violence. The results support crime prevention policies that target the disruption of gang retaliations.

中文翻译：

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帮派暴力犯罪是否比非帮派暴力犯罪更具传染性？

目标

帮派被认为会加强对暴力的参与。预计与帮派有关的暴力犯罪会以传染性的方式引发更多犯罪，超出非帮派暴力犯罪的典型情况。

方法

本文使用多变量自激点过程模型来估计洛杉矶近期数据中与帮派有关的和非帮派的严重袭击和凶杀案中暴力犯罪的传染性传播程度。还估计了与帮派有关的暴力犯罪和非帮派暴力犯罪之间的传染性交叉触发程度。

结果

与帮派相关的暴力引发的后代事件是非帮派暴力的两倍，而且很少或没有交叉触发。与帮派相关的后代事件比非帮派后代事件更致命，但不比非传染性背景帮派犯罪更致命。

结论

与帮派有关的暴力犯罪的传染性传播不同于非帮派暴力的传染性。结果支持针对打击帮派报复的犯罪预防政策。