Why does the public conversation deviate so markedly from the facts?

The tone and language are somewhat off or needlessly combative but The Gun Homicide Epidemic Isn’t by BJ Campbell raises couple of interesting points. His topic is interesting and factually treated but I think he undermines it through the occasional left:right reference.

How can there be such a sustained mismatch between facts and policy conversations?
Why is there such gun control enthusiasm in some quarters when gun violence is at an historic low?
Why is the focus on gun ownership rather than governmental effectiveness?
Why is suicide prevention being ignored in pursuit of gun control?
What are the underlying causes of violent crime, why is it higher in the US than other OECD countries, and why does there appear to be a cyclicality to that violence?
Why do our major institutions of knowledge generation and conveyance (universities and mainstream media) fail so significantly in terms of accuracy, precision, and the scientific method?
What is the link between violent crime and substance abuse (drugs and alcohol)?
What role does the mainstream media play in trafficking in false knowledge, cause or effect?
Why is there such a common media inclination to focus on the incidental rather than the causally substantive?

Beyond these questions raised or implied by Campbell, there is another.

Why is there not more attention on government culpability and policy with regard to violent crime?

In at least a plurality of mass shootings, if not a majority, in the past decade, the shooter was an individual already known to the authorities as a risk. Pulse Night Club, Parkland School Shooting, San Bernardino, Boston Bombing, Garland Texas, Fort Hood, etc. All incidents of violent crime where the perpetrators had been previously investigated or were being actively monitored.

Is there anything that might be done to improve the security through more effective policing? Given the frequency with which actual violence is committed by previously known attackers, it seems to be a reasonable question and yet it is rarely a part of the conversation.

I am not predisposed one way or another. I suspect there might be two strong cases to be made against the charge of policing incompetence.

Humans are inherently unpredictable and our forecasting capabilities regarding human intention are simply too rudimentary to be useful.

The police already forestall a great majority of planned incidents and those that do occur are in fact rare exceptions.

Both are credible arguments but I am not familiar with research, if it exists, that might answer the question and neither proposition is self-evident. The puzzle is that there is not much discussion of those obvious propositions.

Similarly, Campbell may be right or wrong in some of his suppositions but he is posing reasonable, in fact necessary, evidentiary questions that simply do not receive much attention. If we are concerned about violence, it is to the evidence we need to be turning, not the emotion and the virtue signaling.