The rate of fire of an assault rifle is no match for a pistol. On top of that the guy was wearing a bullet proof vest and has thrown tear gas in a confined room while wearing a gas mask and night vision goggles.
I havent paid any attention to the details aside from a crazy guns down innocent folks.
fully auto assault rifle? other then that only advantage is more powerful and more shots before reloading.
but the tear gas and dark would be in his favor no doubt

as for a vest... even 1 direct hit anywhere except the vest would have slowed and/or stopped him( even if just for a moment)
maybe not if he's whacked out on angel dust, ice, etc...
you think he went in there expecting return fire or just shooting targets sitting in chairs?
anyway, my point is if more citizens carried protection and were trained to use them instead of being scared of guns incidents like this
MIGHT have less chance of occurring.
but more so robberies, like Archie's vid

IMO all the thugs would have a 2nd thought about robbing someone/someplace if they had even a slight chance of being confronted with an equalizer like the old man in vid
maybe just way I was raised..IDK but some of my earliest memories are my dad taking us to shoot and teaching us gun safety.
so if for some unlikely chance we had to use a gun at home alone then we knew what to do.
he said just make sure to drag them in the house before calling the cops
