I can state with great certainty that more firearm legislation will not stop these types of crimes.
The ultimate problem is people.
With all respect, I disagree .. it depends on what kind of firearm legislation …
if it is more bans, prohibitions, confiscations, etc - then no, it's a dead end ..
the main lesson from the NS event - inability of the police and authorities to provide any safety and/or protection .. for hours, forget minutes and/or seconds .. and seconds what's needed
but if it's a firearm legislation getting vetted people trained, tested, qualified in Use of Force Models and using handguns, allowing them to carry
(personally, I prefer open and not concealed) to protect themselves and fellow citizens - then yes, it will help …
why, IMHO, it should be trained, tested and qualified people? …
because UoFMs are different for different categories of people - LEOs, armed guards, armed civilians, and they are quite complex ..
and everyone carrying must be able in a split second identify if someone is behaving in accordance to their appropriate UoFM or not
and choose his/her own actions in accordance to his/her own UoFM … any error will have a dire consequences …
and be proficient in the use of a handgun, as on the streets, not in a controlled environment of the ranges, there are no missing shots …
every bullet meets a target … the problems is, was it an intended and legitimate target … if not, the shooter is fully responsible …
and again, with dire consequences ...