Although her book does not deal with Canada's history of school shootings, it takes little time to recognize the similar dynamics underlying these events. Newman makes the point that there is no single explanation, but usually five conditions set the stage: the killer's perception of himself as socially marginal; psychological and social problems that increase the impact of his marginal involvement in everyday life; a failure of society to identify troubled young men before they act; cultural support for the view that firearms can work to solve social problems; and the relatively easy availability of guns (in this case a semi-automatic military assault rifle).

From what we know about Kimveer Gill, these conditions were met. He was socially marginal, a self-described "angel of death," picturing himself on a website with his registered semi-automatic military assault rifle, and obviously approving of the use of guns as a way of resolving social problems.

It is, of course, not entirely correct to say that nothing can be done about this kind of crime. The federal government's tolerance of semi-automatic military assault rifles in the hands of civilians is a policy that could and should be changed. Holmes and Holmes go on to identify various types of mass killers: disciples, those who annihilate families, disgruntled employees ("going postal"), the ideologically motivated, the psychotic, the angry citizen and school shooters. At its most extreme, mass murder can be an act of genocide, as in Rwanda.

Like most researchers who have studied the phenomenon, Holmes and Holmes appear to hold out little hope that mass murder will disappear from our world, as long as a culture of firearms violence continues to exist, as long as other means of mass destruction are also available, and as long as the media provide publicity, and hence inadvertent "glamour" to such events, leaving open the door to copycat killings. The intent of the book is to allow readers, and by extension law enforcement, to distinguish types of mass murder and their motivations, and more effectively to confront potential problems in the investigation of these crimes.

Richard Wrangham and Dale Peterson's (Houghton Mifflin, 1996) is a "big picture" book -- one that allows us to step back from the specifics of the Dawson College killings and raise questions about the more general and persistent problem of male violence, and its trajectory from apes to humans. The authors point to the reality that male violence has structured the lives of humans and chimpanzees for thousands of generations, and that it has, historically, been a successful evolutionary strategy.

Wrangham and Peterson are, however, not simply biological determinists; they point to the bonobos, pygmy chimpanzees that often settle disputes through sex, as a hopeful example of a more peaceful future. And they argue that violence is no longer a useful evolutionary strategy in the global context of the 21st century. Amen to that.

Neil Boyd is a professor of criminology at Simon Fraser University, and the author of seven books, including The Last Dance: Murder in Canada and The Beast Within: Why Men are Violent.

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