So, I read somewhere he had on body armor.
My guess is that he had one of these $108 black "urban assault tactical vests," worn by some shooters (and urban assault fisherman ;-) Same kind the Batman theater killer ordered from tacticalgear.com.
Guaranteed to stop nothing, including the breeze that blows through the enormous gap in the middle of the chest.
In that Colorado theater shooting, one or two decently-trained civilians (and I know plenty of them personally) armed with concealed .45s, could have disabled that shooter quickly and saved lives. In times of stress, the eyes often dilate and give you the ability to see in the dark, and also they could identify the location of the shooter by his muzzle flashes. It is SICK and DISGUSTING to see how many self-described "experts" here are falling all over themselves to try to convince people that they should roll over instead of fight back.
ANYBODY here who tells you that body armor makes the shooter impervious to concealed-carry defense of higher caliber like .45s, is LYING. You have to wonder why.