Historically speaking, the truth is that rates of gun crime rise when guns are made illegal. And they fall when guns are legalized.
The US States with the highest rates of gun crime are those with the most stringent laws against gun ownership.
The US states with the lowest rates of gun crime are those where gun ownership is legal.
The countries where guns are legal, and virtually every adult owns one, have very low rates of gun crime (Cuba, Switzerland).
The countries where guns are strictly illegal, so only criminals own them, show massively high rates of gun crime (Jamaica, Mexico).
And that's quite apart from the moral and political issues involved. People should have the right to bear arms in order to defend themselves (a moral right) and in order to defend themselves from tyranny (a political right).