King Douglas M, Jacobson Sheldon H
Violence Vict. 2017 Dec 1;32(6):1014-1023. doi: 10.1891/0886-6708.VV-D-16-00039. Epub 2017 Oct 10.
Recent mass killings, such as those in Newtown, Connecticut, and Aurora, Colorado, have brought new attention to mass killings in the United States. This article examines 323 mass killings taking place between January 1, 2006, and October 4, 2016, to assess how they are distributed over time. In particular, we find that they appear to be uniformly distributed over time, which suggests that their rate has remained stable over the past decade. Moreover, analysis of subsets of these mass killings sharing a common trait (e.g., family killings, public killings) suggests that they exhibit a memoryless property, suggesting that mass killing events within each category are random in the sense that the occurrence of a mass killing event does not signal whether another mass killing event is imminent. However, the same memoryless property is not found when combining all mass killings into a single analysis, consistent with earlier research that found evidence of a contagion effect among mass killing events. Because of the temporal randomness of public mass killings and the wide geographic area over which they can occur, these results imply that these events may be best addressed by systemic infrastructure-based interventions that deter such events, incorporate resiliency into the response system, or impede such events until law enforcement can respond when they do occur.
近期发生的大规模杀戮事件，比如康涅狄格州纽敦市和科罗拉多州奥罗拉市的惨案，让美国的大规模杀戮事件再次受到关注。本文研究了2006年1月1日至2016年10月4日期间发生的323起大规模杀戮事件，以评估其随时间的分布情况。具体而言，我们发现这些事件在时间上似乎呈均匀分布，这表明在过去十年里其发生率保持稳定。此外，对这些具有共同特征（如家庭内部杀戮、公共场所杀戮）的大规模杀戮事件子集的分析表明，它们呈现出无记忆性，这意味着每类大规模杀戮事件都是随机发生的，即一次大规模杀戮事件的发生并不能预示另一起大规模杀戮事件是否即将发生。然而，将所有大规模杀戮事件合并进行单一分析时，并未发现同样的无记忆性，这与早期研究结果一致，即大规模杀戮事件之间存在传染效应的证据。由于公共场所大规模杀戮事件在时间上具有随机性，且可能发生的地理区域广泛，这些结果意味着，对于此类事件，或许最好通过基于系统基础设施建设的干预措施来应对，这些措施可以威慑此类事件的发生，在应对系统中融入恢复能力，或者在大规模杀戮事件发生时阻碍其发展，直到执法部门能够做出响应。
