To establish that fact, you'd have to engage in a psychological examination of the criminals.
No, you would not. Because the evidence is simple. The vast majority of the types of murders we're talking about are conducted by people illegally owning guns, most of which are stolen or otherwise illegally in possession of the person doing the deed. If criminals cared about illegally possessing guns, that simple fact wouldn't be true. There's no need for hand-wringing psychoanalysis ... just open your eyes.
This sentence, your basically saying solving the problem solves the problem.
No, I'm saying that solving the crime problem happens to solve the CRIME WITH GUNS problem. But the gun control think (or pretend to) that guns CAUSE the crime. I'm pointing out that they're being completely disingenuous, because they know that the problem is crime, not guns. They don't want to confront the human behavior part, because that means being judgmental about other people (and statistically, being judgmental especially about poor people and minorities) that are involved in most of that crime. Because that's the third rail of political correctness, they lazily pretend that controlling the guns that non-criminals might purchase will make crime go away so they don't have to confront the real problem: local culture.
And yet that is a contention that hasn't been proven, actually.
That's why you can't make any assertions about local gun laws, as the effect of local gun laws on the availability of guns has not been demonstrated.
It doesn't NEED to be. Unless you're suggesting that gun control laws make guns MORE available in the areas where they are used frequently in crimes. Is that really your contention? Otherwise guns are uniformly available across the country, but at least somewhat less so in areas like Chicago because of the draconian laws (which is why people who wanted to own them for self defense in their homes there had to take the matter to court).
First you have to reduce the supply of guns, then you can see what impact it has on the crime levels.
Why? We already see that crime level are much, much lower in most areas where guns are readily available. Guns are harder to legally purchase in Chicago, where they have a huge crime problem. Guns are readily available in other cities, where they do not have that problem. What if Chicago's laws have NO impact on gun ownership levels. So what? Let's say it is has zero effect, and that guns are just as available there as the are in, say, San Diego or Hartford. So what? The differential in crime is enormous. If you're really going to pretend that can't grasp that, then there's little point in continuing the conversation, because you're not fooling anybody.