Mass violence, to the limited extent that it is due to mental illness, may best be prevented by providing competent and comprehensive mental health care to the American population (a situation that doesn’t currently exist) and, in this context, adopting a public health model of prevention:
• Universal: A public education campaign to help identify people of concern (e.g., “see something, say something”).
• Selective: Measures to assess and intervene with people with specific identified warning signs — but no history of past significant violence, communication of threat or evidence of planning — and access to weapons capable of inflicting mass casualties.
• Indicated: Measures to contain, assess and intervene with people with past histories of threatened or actual significant violence, specific warning signs that include communications of threat and evi- dence of planning/practice and access to weapons capable of inflicting mass casualties.
It is important to note that most of the people who pose a risk of violence are not hidden from view. In the right kind of organizational setting — whether community, workplace, health care or educational venues — people exhibit signs with what they say, do and how they behave that reveal their distress or propensities. Some of them overtly threaten violence, recruit accomplices, talk about their violent acts and clearly need help. But there’s a broader pool of people who are in urgent emotional distress. They might have a mental illness, but their distress may be circumstantial, caused by a domestic dispute, a setback or disappoint- ment in their job, financial duress or a combination of events. In such conditions there are interventions that can defuse the situation and move people off the pathway to violence well before they show up with a gun. And while it may not be possible to precisely determine if and when their suspected untoward behavior might emerge, creating within an organization a place where a person who sees something can say something and know that their concerns will be acted on is a powerful public health intervention. It also becomes an important basis for getting information about who might cause harm.