I posted the article from a biased publication because it gave actual citations, not just unsupported arguments. Keck hasn't been debunked. There are criticisms of  the limitations but not it hasn't been debunked. The Harvard article doesn't even mention Keck.

The Harvard article makes problematic claims. 1st it makes judgement calls about being undesirable. Red flag of bias here. Then it suggests that juveniles are more likely to be threatened with a gun than to use it for self defense. Duh, kids aren't allowed to carry guns so of course incidents where they use them in defense are less common. Also the author reasons that guns aren't really used in self defense that often because there aren't enough gun shot cases in ER rooms. This ignores that a gun doesn't have to be fired to be effective in self defense. 

Like I said, lets say the number was much smaller, 10k or less. Taking away guns will mean those people will be killed, raped, or assaulted. Will their blood be on your hands?