I don't see that he suggested a solution. Just the opposite, he pointed out that gun laws also aren't a solution. Much like the war on drugs isn't. Much like "though shalt not kill" didn't stop the inquisition, or the Moorish conquest.
No murders? No. You should read about the "Nirvana fallacy".
Fewer murders? Yes. The homicide rate is 0.854 per capita in Australia (5.763 in the US) and much lower than US in most European countries (Russia being the exception).
But are we suggesting that he should have deployed counter snipers?