We understand why violent behavior occurs and the catalysts that drive sociopath/psychopathic/disassociative behavior, that was never in doubt. Though the issue is most certainly a human one, the debate about it skips over a most important detail, lack of a "one true method" to curb gun violence doesn't mean no methods should be experimented with. We need to treat the symptoms while we wait for a cure. For example, firefighters put out the fire before figuring out how to prevent it from happening again, they don't question it's genesis and reasoning before stopping it from hurting anything else. We will never suppress violence as a species, it is too natural to us, it is in our DNA, but taking away the tools needed to indiscriminately kill people by the dozens in a matter of minutes or even seconds is a way to keep the inevitable violence of an individual from effecting the lives of hundreds. The gun debate isn't about stopping the human propensity for violence, it is about stopping the devastating violence of people who otherwise would not have killed anyone if not for access to a tool whose only purpose is to kill and to make killing easy. Violence can be sourced back to human nature and environmental factors as well as a genetic predisposition to mental disorders, but the exponentially increasing trend of brutal gun violence can be traced to one source, guns. It is the gun itself that empowers the mentally weak and disturbed to act on their violent thoughts because if all they had was a knife or sword they would of probably never even attempted or if they did it would of never affected the lives of so many innocents. Also it IS easy to group humans based on behavioral patterns and mental health, there is a whole field of study and science dedicated to it. There is historical precedence and a clear pattern showing what increases violence, inequality, and by the laws of equivalency, in this case material equivalence, increasing equality would decrease violence. Among the many known effects of inequality on a society are social unrest, a decrease in health, and a distinct lack of solidarity; all of which lead to violence in one form or another. Unfortunately humans have never been good at decreasing inequality peacefully, as historically, the only effective methods for doing so have been plague, massive warfare, or revolution. So in essence we will never be rid of violence nor will we be able to prevent it all together, but what we can do, as a society, is work towards making it harder for those who wish to commit violence, regardless of why, to actually do so, so that we may discuss and figure out solutions without more bodies piling up.

Let me start by stating that I sold firearms for a living and own firearms for self-defense and sport shooting. Now that that is out of the way...

It is hard to say what the cause of gun violence is seeing that in each case the reasoning is different. Mental illness is minor on the list. Domestic disputes, general anger towards society or occupation, The "boys" involved in the Columbine massacre were not mentally deranged but angery at their fellow students for not taking them seriously. The guns were purchased by a fellow student legally as a straw purchase which was not considered a problem in 1999. Since then most of the mass shootings (where five or more have been shot and killed per the FBI) where committed out of anger, a few because of terrorism and a small number because of mental illness. (https://www.vox.com/policy-and-politics/2017/11/9/16618472/mental-illness-gun-homicide-mass-shootings)

The problem is, in part, that it is so easy to purchase a gun in the US. The Las Vegas shooter purchased his rifles legally, transported them "legally."

Th US has more mass shooting than the next ten industrial countries combined. We need to allow studies of gun violence by the CDC and others, paid for by the government, which is currently prohibited because of the lobbying efforts of the NRA. If we cannot study the problem, how will we find a solution to what seems to be a weekly occurrence?

You ramble all over the landscape. Again, your point?

The NRA will try to get anybody to blame gun violence on anything if it gets them to not blame it on the availability of guns. That's the influence of money for you.

having guns is one fairly universal reason