Over the last few years, there has been a series of high-profile, premeditated ambush attacks on police, which has led some to conclude there is a “war on cops.” Unfortunately, prior research has not examined the prevalence of police ambushes over an extended period of time, and the most recent study only analyzed the phenomenon through 2013. Moreover, the “war on cops” thesis implies a very specific motivation for an ambush: hatred of police or desire to seek vengeance in response to police killings of citizens. Prior research has not sufficiently explored the motivations of ambush attacks, or whether recent trends in ambushes are linked to a “war on cops” motive. I investigate ambush killings of police from 1970 to 2018 using data from the Officer Down Memorial Page in an attempt to address these research gaps. I apply a temporal coding scheme of when the attack occurred to isolate killings of police that are consistent with the International Association of Chiefs of Police definition of an ambush. Results from linear regression show that the annual rates of ambush killings of police have declined by more than 90% since 1970. Although ambushes spiked in 2016 and 2018 to the highest rates in 20 years, interrupted time series analysis indicates no statistically significant increase post-2013. Spikes have also occurred in nonambush killings since 2014. Police leaders and researchers should monitor trends in ambush and nonambush killings of police, as the recent spikes may presage the emergence of a chronic problem.

在过去的几年中，发生了一系列针对警察的高调，预谋性伏击攻击，这使一些人得出结论认为，这是一场“警察战争”。不幸的是，先前的研究并未检查过长时间以来警察伏击的普遍性，而最新的研究仅分析了直到2013年的现象。此外，“警察战争”论文暗示了伏击的非常具体的动机：仇恨警察或为报复杀害公民而寻求报复的愿望。先前的研究不足以探讨伏击袭击的动机，或伏击的最新趋势是否与“警察战争”动机有关。为了解决这些研究空白，我使用了下来官纪念页面上的数据调查了1970年至2018年的伏击杀害警察事件。我采用了一种临时编码方案，将袭击发生的时间与国际警察局长协会对伏击的定义保持一致，以隔离杀害警察的行为。线性回归的结果显示，自1970年以来，每年的警察伏击杀害率下降了90％以上。尽管伏击在2016年和2018年达到了20年来的最高水平，但中断的时间序列分析表明， 2013。自2014年以来，水am虫杀害事件中也出现了尖峰事件。警察领导人和研究人员应监视警察伏击和水am虫杀害事件的趋势，因为最近的高峰可能预示着一个长期问题的出现。