But that is how science works. You dont trust one study, you like to see study after study from completely different people come to the same conclusions using unbiased methods before using it to make big decisions.
Not really. Anything having to do with social science is typically a joke in the scientific community (real science, as in physics or biology).
I used to read the anti-gun studies for "fun", and even a lay person could see the problems with them. Murder rates depend on a vast number of variables, and anyone who thinks he can reduce them more than a bit by fiddling with gun laws is just flat-out lying or ignorant. And that's ignoring the potential for gun laws to facilitate enslaving the population; slavery causes a high death rate too, something never factored into these studies.
But who is paying attention to this crap any more? Maybe what motivates these studies is attracting grants from the Bloombergs of the world.