If you think this horrible event isn't being exploited by the anti-gun crowd, ask how many people are killed each year by "assault weapons".
I don't know the answer, but in 2011 there were 323 homicides using rifles of all kinds. 323 out of 12,664 homicides. Hands and fists killed 726. FBI — Expanded Homicide Data Table 11
Since the large majority of rifles are not "assault rifles", it looks to me like a total ban of all assault rifles wouldn't have much impact on the number of murders. Nor are rifles the easiest way to walk thru a "No Gun Zone" like schools killing people. Handguns would be easier to conceal until the last moment, and you can carry a lot of them. Nor will banning large capacity magazines help, since large capacity magazines are more likely to jam - as one did in Colorado.
Yet what are the politicians focusing on? Banning assault weapons (aka 'scary looking rifles') and banning high capacity magazines. Or expanding the "gun free zones", which would be better described as places where only criminals and lunatics have access to guns.
Nor are pro-gun "nuts" exploiting this event. Gun owners only got involved after many calls for gun bans and gun registration and restrictions on carrying concealed weapons were proposed. The NRA refused to make any comment other than one of sympathy until after the politicians started talking about gun bans.
It seems to me there are two pretty common threads in these mass shootings: nuts who cannot be committed or registered as mentally dangerous, and gun free zones.
Oh...and it takes almost no training to shoot a gun from close range at unarmed people. Skill only comes in when the victim has the chance to fight back...