Due to my profession I have studied this in depth and attended many seminars on the subject-I say this (humble opinion of course):
If my daughter was one that had been murdered I admit I would probably side with the gun ban crowd. I probably wouldn't be able to help myself and I would need some sort of immediate remedy to feel like I had some control. But being in law enforcement allows me somewhat different perspective on the why's, how's, and all the other questions we are forced to keep asking our society.
Through the military and my current profession I have seen death and pain more than I ever would care to. I see a lot of other veterans on this site and am sure some of you can relate. Usually it is the innocent that are hurt and, in my experience, the bad people that get to enjoy all the freedoms and safeguards that our society provides. It is difficult to watch and even more difficult to be a part of that "system" that appears so unjust.
That being said, I am of the opinion that firearms or gun control are but a distraction of a much more sinister issue. Regarding firearms, the technological advances made in the past 100 years have done almost nothing to increase the lethality of firearms. The 1911 pistol (I believe created in 1908; I know some gun guy is going to correct me) held about seven rounds and fired in semi-automatic mode. The Browning automatic rifle (1915ish - .308 caliber - 10 rounds), Thomson sub-machine gun (1919ish - .45 caliber - 20-100 rounds).
The point is that the lethality of firearms has remained steady. The main difference now, in technology, is the weight reduction and a greater ease in reloading capability. Magazine capacity has only slightly increased in general.
School shootings, public shootings, usually ending in suicide are a relatively new phenomenon. Something has changed in the last ten to fifteen years and it hasn't been firearms. Col. Dave Grossman has written several fascinating books on the subject "On Combat", "On Killing", "Terror at Beslan" and a few others. What can be seen in studies is that violence has drastically increased with the availability of television and video games. These studies have been shown to correlate the recent rise in violent activity with the prevalence of the horrific movie genre and violent gaming industry.
I remember watching Gary Cooper and others killing people in movies but the messages of movies were different. Cooper played a sheriff in High Noon where he killed multiple people but he was reluctantly fighting against bad guys who were out to do harm. He was clearly wearing the white hat. Older movies show the good guys fighting the bad and draw a clear distinction between them.
I admit that I am a big fan of the man with no name series, but the hero, Clint Eastwood, is a bad guy. Newer movies have taken this even further. Most movies now are "root for the bad guy" films. The hero does terrible things for the sake of doing terrible things. They hunt down, admittedly bad people, and kill them but, in so doing, commit atrocities themselves. These atrocities are considered necessary to get things done and justified by the "even worse" bad guys. One only need watch shows like Boondock Saints, Reservoir Dogs, Saw, or Natural Born Killers to see this change. Some are outright snuff films.
Video games are much much worse. There are main stream games like Grand Theft Auto where you play the main character, an ex-con just released from prison. The point of the game is to complete a storyline that is rife with graphic displays of drugs, sex, and murder. During the game you steal every vehicle you find and kill the police who inevitably attempt to stop you. The more police and citizens you kill the more points you rack up.
Games nowadays are based on killing everything you see. The killing is more insidious because the gamer plays a bad person likely killing police and innocent people for extra points. The kill count is what is important and the more gruesome way things are killed the more the in-game reward.
Check out these games to understand what kids are playing: Postal 2, Grand Theft Auto 3, and Manhunt. There is even a game that replays the Columbine massacre albeit it is not mainstream.
Correlation does not always mean causation but one cannot overlook the almost perfect correlation between workplace violence and the video game culture.
On a side-note, I recently attended training where a psychiatrist spoke about the "me culture". An interesting topic, his theory is that kids are told from a young age that they are wonderful and cannot fail. Everyone gets a trophy and a chance to play so that nobody ever has their feelings hurt or their self esteem damaged. When they get a bit older, late high-school and early adult-hood, they have never developed the coping mechanisms against real life situations that previous generations have and they "lose it".
I don't mean to debate anyone or debase arguments made against firearms from other members here. I respect everyone's opinion. Just my 2-cents.