A non-violent society will have lower homicide rates no matter what the gun laws are.  See the link.  In the US we have a higher homicide rate without firearms than much of western Europe has for firearm and non-firearm homicides combined.  As an historical reference New York had a homicide rate several times that of London before either city had any gun control laws.

Link

Listen to what he proposes:  "first, those who acquire credible evidence of an individual's mental disturbance should be required to report it to both law enforcement authorities and the courts, and the legal jeopardy for failing to do so should be tough enough to ensure compliance"; those reporting obligations should apply not only to family and friends, but extend to "school authorities and other involved parties."  And "second, the law should no longer require, as a condition of involuntary incarceration, that seriously disturbed individuals constitute a danger to themselves or others"; instead, involuntary commitment should be imposed whenever there is "delusional loss of contact with reality."  He concludes on this melodramatic note:  'How many more mass murders and assassinations do we need before we understand that the rights-based hyper-individualism of our laws governing mental illness is endangering the security of our community and the functioning of our democracy?"

Glenn's response - offered in part, below - is one we all need to be reminded about:

What Galston is doing here is what the American political class reflexively does in the wake of every tragedy:  it immediately seeks to exploit the resulting trauma and emotion to justify all-new restrictions on basic liberties (such as the right not to be locked away against one's will in the absence of a crime or a serious threat to others) and all-new government powers.  Every traumatic event -- in the immediate, emotionally consuming aftermath --  leads to these sorts of knee-jerk responses.  The 9/11 attack immediately gave rise to the Patriot Act, warrantless eavesdropping, a torture regime, due-process-free imprisonment, and ultimately an attack on Iraq.  High-profile, brutal criminal acts have led to repressive measures such as three-strikes-and-out laws and minimum sentencing guidelines, causing the U.S. to maintain the largest Prison State in the world.

[snip]

What lies at the core of this mindset is desperate pursuit of a total illusion:  Absolute Safety.  People like William Galston believe that every time there is a violent or tragic act, it means that the Government should have done something -- or should have had more powers -- in order to stop it.  But that is the reasoning process of a child.  Even if we were to create an absolute Police State -- the most extreme Police State we could conjure -- acts like the Arizona shooting would still happen.  There are more than 300 million people in the U.S. and, inevitably, some of them are going to do very bad and very violent things.  Thus has it always been and always will be.  The mere existence of bad events is not evidence that the Government needs to be more empowered and liberties further restricted.  Just as there are serious costs to things like the Arizona shootings, there are serious costs to enacting the kinds of repressive systems Galston envisions, yet people like him never weigh those costs.

Having people do bad things is the price we pay for freedom.  There is a cost to all liberty.  Having to hear upsetting or toxic views is the price we pay for free speech; having propaganada spewed by large media outlets is the price we pay for a free press; and having some horrible, dangerous criminals go free is the price we pay for banning the Police from searching our homes without a warrant (the Fourth Amendment) and mandating due process before people can be imprisoned (the Fifth Amendment).  The whole American political system is predicated on the idea that we are unwilling to accept large-scale abridgments of freedom in the name of safety, and that Absolute Safety is a dangerous illusion.  There is a new report today that a police officer in Tuscon stopped Jared Loughner's car for speeding shortly before his rampage, but was unable to search his car because he lacked probable cause to do so.  Obviously, that's regrettable -- if you're a family member of one of his victims, it's horrifying -- but the alternative (allowing Police the power to search whomever they want without cause) is worse:  that's the judgment we made in the Bill of Rights.

I think far more than the ugly rhetoric that has become acceptable in some quarters, or the widespread availability of guns, what is poisoning our country is the way we are addressing the country's social ills: too many people without health care, going to bed and to school hungry, living in sub-standard conditions or existing in shelters, unable to find work.  

Quality of life in this country is declining for far too many people; when you are sick, hungry, jobless, homeless, and see no help or relief in sight, it tends to have a negative effect on one's mental health; anger ensues when people see, and believe, that it is, in large part, the action - or inaction - of the government that is hurting their ability to crawl out of this hole, and desperate people do desperate things.