We still don't understand why a gunman opened fire at a school in Connecticut, killing 26 people, including 20 children.

John Moore, Getty Images

Dr. Joel Dvoskin, a Fellow with the American Psychological Association, says, "Younger men are the ones committing most of these crimes, and usually they are deeply disaffected, disconnected, in despair and typically enraged."

He says, "There have been some cases of women committing mass murder, but it is overwhelmingly more prevalent among men- and I'm not sure what the reason is…Even though, lately there's been an increase in crimes committed by girls and women, but it's still far less than violent crime among men - some people think it's hormonal, others think it's sociological, and I honestly don't know."

Dr. Dvoskin adds, "There is a lot of evidence that violent imagery in television, movies , video games and television news have a bad effect on violence - that people who watch violent imagery are more likely to be aggressive or violent than people who don't, but that's a far cry from saying violent imagery caused an incident like this…there's a lot of rage in America, but most of the people who are enraged will not do anything stupid, so the issue then becomes, why would someone be willing to essentially take their own life and bring a bunch of people with them?... So one way to think about them that might be useful for us is to think of them as suicides- because we know something about preventing suicide…one of the ways we prevent suicides is by making it possible for people who are in crisis to get timely help."

He also says one reason why we're seeing more of these horrible incidents is, "the way in which the national media treat these events …what Marilyn Manson ironically called a market for mass murder…if you're feeling insignificant, enraged and disconnected, with nothing to live for, one guaranteed successful way to become the most fascinating person in America, for a few week weeks, is to kill a bunch of people…we've been arguing for decades how to stop the national media from glorifying these crimes and criminals- they should report the news, but that's it - they shouldn't show the person's face for days and days and days on television, and have these mindless fools speculating about their motivations."

When asked what's causing this rage, the professor said "You know I wish I knew, I'm not sure about that to be honest with you… there are many troubled individuals in the world, but it's almost impossible to know ahead of time which troubled person out of millions is going to commit an act like this."