you are in effect shifting the argument away from what was originally stated.
What I stated, and have always stated, was that MORE regulation will not likely impact the homicide rate in any significant way, nor will it likely stop the incidence of such rampage attacks. The reason for this is painfully obvious to all except anti-gun nuts: such homicide rates have more to do with socio-economic or mental illness factors than the number or types of guns available. Gang killings and rampage killings involve people who have already decided to break the law. No amount of regulation is going to stop someone who has already decided to ignore the law. The only effect of regulation is increased encumbrance on law-abiding citizens.
The only logical conclusion of your position is to outright ban all firearms, and that will simply not work. 1) because there will always be guns available to those who want one badly enough (look at the supply and demand of elicit drugs and criminal possession of "illegal" guns, not to mention legitimate sources such as hunters, law enforcement, target shooters), 2) even without access to firearms, those who are bent on harming others will resort to other means (blunt weapon or knife/sword attacks, improvised explosive devices, vehicular homicide, poisoning, etc, etc, etc).
This knee jerk reaction against the gun instead of the perpetrator is as understandable as it is useless. But to effectively deal with these situations, solutions must address why the perpetrator committed this crime. Simply adding more regulation or arbitrarily banning certain firearms (as we do in Canada) will ultimately have no effect on mitigating such outcomes.
Why? For the simple reason that those who choose to ignore the law will simply ignore the law.
You're post introduces a slew of other situations (suicide, accidental deaths, firearms deaths apart from overall homicide rates, etc., etc) that have nothing to do with random or deliberate homicides. For the sake of argument, let's try to keep the topic of conversation consistent to the one at hand.
Also keep in mind that relative to other US states, Connecticut is reported to have some of the more stringent regulations, and that the perpetrator of this crime had been denied a firearms permit.