The impact of terrorism on homicide and suicide: An interrupted time series analysis of September 11 and Oklahoma City.

There is substantial evidence that catastrophic events, including terrorist attacks, lead to increased levels of post-traumatic stress, especially in communities in close proximity to the incident. Some scholars also argue that these events disrupt social organization. On the other hand, many contend that these incidents produce social cohesion as community members coalesce to help each other in time of need. These ideas have resulted in competing hypotheses in the literature. The first is that violence directed at the self and at others will increase in the wake of catastrophic events due to heightened levels of individual stress and community disorganization. The second is that violence will decline after these events because of increased social cohesion, especially in the face of an outside threat. In order to test these competing hypotheses, we employed autoregressive integrated moving average (ARIMA) techniques to model the impact of the September 11 attacks and the Oklahoma City bombing on monthly homicide and suicide counts at the local, state, and national levels. We found no support for either hypotheses as they related to levels of homicide, though there is some support for the effects of terrorist attacks on levels of suicide. [ABSTRACT FROM AUTHOR]