Introduction

The most widely used data set for studying police homicides—the Supplementary Homicide Reports (SHR) kept by the Federal Bureau of Investigation—is collected from a voluntary sample.

Materials and Methods

Using a journalist-curated database of police-related deaths, we find the SHR police homicide data to be substantially incomplete. This is due to both non-reporting and substantial under-reporting by agencies. Further, our inquiry discloses a pattern of error in identifying “victims” and “offenders” in the data, and finds that investigating agencies are often incorrectly listed as the responsible agency, which seriously jeopardizes police department-level analyses. Finally, there is evidence of sample bias such that the SHR data system is not representative of all police departments, nor is it representative of large police departments.

Conclusions

We conclude that the SHR data is of dubious value for assessing correlates of police homicides in the United States, as all analyses using it will reflect these widespread biases and significant undercounts. Analysis of SHR data for these purposes should cease.

中文翻译：

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评估联邦调查局补充凶杀报告中正当凶杀的数据完整性、质量和代表性：研究报告

介绍

用于研究警察凶杀案的最广泛使用的数据集——联邦调查局保存的补充凶杀报告（SHR）——是从自愿样本中收集的。

材料和方法

使用记者整理的警察相关死亡数据库，我们发现 SHR 警察凶杀案数据基本上不完整。这是由于各机构不报告和大量少报造成的。此外，我们的调查揭示了数据中识别“受害者”和“犯罪者”的错误模式，并发现调查机构经常被错误地列为责任机构，这严重危害了警察部门层面的分析。最后，有证据表明存在样本偏差，SHR 数据系统不能代表所有警察部门，也不能代表大型警察部门。

结论

我们的结论是，SHR 数据对于评估美国警察凶杀案的相关性的价值值得怀疑，因为使用该数据的所有分析都将反映这些普遍的偏见和严重的漏报。出于这些目的对 SHR 数据的分析应该停止。