May I add my mustard to this: I'm from Austria, a small country in europe. We have very strict gun laws and if you have a gun there are heavy regulations (I think that even the police comes by when they like and check whether you store the gun right).
Nevertheless, last year we had an incident where one guy shot some people and hid in his house. When the Cobra (like SWAT but more elite) entered his house, they found I think hundreds of weapons.
Also some days ago they found another storage of weapons of another guy.
The moral of the story: There are so many guns that gun laws don't really make much sense in my eyes. Yes, Governor Cuomo might see that differently, and he and the other guys on his side are theoretically right too, but the bad guys will also get the guns if they want. If that's the case here in Austria (and believe me I don't know our and your gun laws exactly, but I guess ours are far more stricter than yours), it can happen in America too (where there's ~1 gun per citizen).
Taking the guns away from the people who only want them to protect themselves and on the other side sending weapons to arabia, from where they again are sent to syria to be used to kill innocent citizens is, in my (closer to Republicans eyes), a very "Democratic" idea, if you pardon that expression.
Yes, the tragedies that happened in America (Columbine, Batman, Sandy Hook,...) are sad, and it requires political action. But I think instead of taking the guns away from the people (what in my eyes means taking them away from the wrong guys as the bad ones will always get their guns) there should be stricter background checks.
Do not mistaken me, I don't share the view of those who want no restrictions on guns. I think Cuomo's plan is a good idea: www.youtube.com/embed/oc74IY1pAeE
He's right in many ways, and yes, those assault rifles should be banned.
So summing up my words: stricter background checks, limit the guns (no assault rifles, not more than eg 15 shots), but don't take the normal, hand-held guns away from the normal people who only own them for self-defense.
Sadly, I don't think any legislature can control this problem, and that such sad events can't be fully prohibited, as there are so many guns in America it's, in my eyes, not possible any more to control each one of them.