The unique parts of Holmes’ kit were a 100-round drum magazine for the M&P15, a gas mask, two tear gas canisters, and what the Aurora Police Department initially claimed was head-to-toe “ballistic” armor. The latter is a claim that has not yet been substantiated, due in part to two gag orders issued by the judge presiding over the case.
The 100-round magazine in Holmes’ rifle has been used by gun control activists to call for the outlawing of “high capacity” magazines. These political creatures argue that high capacity magazines enable criminals such as Holmes to fire more bullets and to kill more people in a shorter amount of time. These same anti-gun activists have little to say when it is pointed out that his decision to use unreliable 100-round drum magazines (there is no such thing as a reliable drum magazine due to their mechanical complexity) is thought to be the reason his carbine jammed and become inoperable. He was forced to transition to one of the Glock handguns, which anecdotal evidence suggests may have been the firearm used to fire half or more of the shots fired in the one-minute rampage.
There is very little that could have been done to prevent an attack that appears to have been months in the planning.
Other firearms could have been used. Many of them are far more powerful than what were used.
If firearms didn’t exist, Holmes had the time, resources, and intelligence to plot something even worse. Timothy McVeigh killed hundreds using nothing more complicated than fuel and fertilizer. Julio Gonzalez murdered 87 with a dollar’s worth of gas. Evil is difficult (sometimes impossible) to thwart beforehand.
Often the only indication of such a violent crime is the outbreak of violence itself, and all the authorities can do afterward is try to pick up the physical and psychological pieces. Ultimately, the survival of the individuals in Theater 9 boiled down to a combination of luck and their own split-second decisions. We can’t do much about luck, chance, or “God’s will.”
There has been considerable speculation about whether a theatergoer with a concealed weapon could have made any difference in the minute-long rampage. Glenn Reynolds pointed out after Virgina Tech that concealed carry at least gives a citizen a fighting chance against an assailant. Frank Taylor and others suggest that there wasn’t enough time, or it was too confusing, or that citizens carrying concealed weapons simply aren’t aware enough, or professional enough, to make any difference.