Holmes stood in front of the theater dressed in black and wearing a gas mask. He was back lit by the screen. Nobody could get to the front exit without going past him, 112 people all trying to get out the back door were massed together making it easy for him. smoke or no smoke nobody was running towards him and it was obvious who the shooter was, where he was and what his intention was. Because all of the people there legally complied with theater policy and were unarmed for their own safety were literally fish in a barrel. One person with a reasonable amount of marksmanship skill and a cool head could have taken Homes out before he killed 12 people.
Lanza was in a gun free zone made so for the express purpose of making a safe environment for the staff and students. He was the only one armed, the only one shooting and nobody could do a thing about it. People bblame the Bushmaster which was not used and they blame his aspergers which rarely ever leads to violence, there were other issues but the biggest one was that nobody could protect the children, one teacher, maintenance man, parent, visiting vendor, somebody, anybody armed with a gun and a reasonable amount of skill could have stopped Lanza, there was no doubt in anybody's mind who was doing the shooting.
When Roberts went on his shooting rampage at the Clackamas mall it was obvious who was the spree shooter. The sight of one person with a gun and the spree ended. Anybody see a pattern here?
Good intentions will always be pleaded for any assumption of power. The Constitution was made to guard the people against the dangers of good intentions. There are men in all ages who mean to govern will, but they mean to govern. They promise to be good masters, but they mean to be masters.