The carnage has compelled many observers to examine the possible reasons behind the rise in mass murder. New York Times columnist David Brooks noted the number of schizophrenics going untreated. Gun control advocates have pointed to the 2004 expiration of the federal assault weapons ban as the culprit, while gun-rights proponents have argued that the body counts would be lessened were more Americans armed and ready to intervene and overtake an active shooter.

When it comes to gun violence, no one can deny that the Summer of 2012 has seemed especially horrific. In May, a disgruntled man, known in the community for his belligerent manner, shot up a Seattle cafe after being denied service, killing five before committing suicide. Then we witnessed the massacre of 12 moviegoers in Colorado and now a rampage at a Sikh temple in Wisconsin that claimed the lives of six worshippers plus the gunman who was killed by the police.

There is one not-so-tiny flaw in all of these theories for the increase in mass shootings. And that is that mass shootings have not increased in number or in overall body count, at least not over the past several decades.

Based on data extracted from official police reports to the FBI, the figure below shows annual incident, offender and victim tallies for gun homicides in which at least four people were murdered. Over the thirty-year time frame, an average of about 20 mass murders have occurred annually in the United States with an average death toll of about 100 per year.

Without minimizing the pain and suffering of the hundreds of who have been victimized in seneless attacks, the facts say clearly that the has been no increase in mass killings, and certainly no epidemic. Occasionally, we have witnessed short-term spikes with several shootings clustering close together in time.

In the 1980s, we had a flurry of postal shootings, and the 1990s included a half dozen schoolyard massacres. Other than the copycatting reflected in these cases, the clustering of mass murders is nothing more than random timing and sheer coincidence.

The lack of any upward trend should not stop us, of course, from trying to find causes and solutions for extreme violence. A fitting the legacy to this summer's tragedies would be the expansion of mental health services. We should also have a serious debate about sensible restrictions on gun sales but absent the politics. And perhaps we should all try harder to reach out to those around us who seem to be struggling financially, socially or psychologically.

Unfortunately and realistically, these and other initiatives may not prevent or deter the next mass murderer living amongst us. But in the process of trying, we may actually enhance the safety and well-being of thousands, if not millions, of Americans.

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