Let me rephrase the recent statements:
(1) If there existed a preponderance of evidence showing that violence
does in fact _decrease_ when people are allowed to freely contact each other, would the proponents of totalitarianism turn into libertarians?
(2) If there existed a preponderance of evidence showing that violence
does in fact _decrease_ when strict military curfew is imposed, and all citizens are allowed to leave their cells and meet only under the supervision of military personnel for productive purposes, would the proponents of individual liberties support the military regime?
You need a lot stronger reasons to deny all people individual liberties and rights of self-protection for the common good, than for letting them keep their freedom.
To decrease violence _and_ increase liberty, the government could legalize marijuana, MDMA and psychedelics. That would remove lots of reasons for offensive use of guns, and make people less likely to use any violence for any other reasons. Easier on the budget, too, than gun control.