Spree killings/mass murders/rampage shooters/whatever are all a canard anyway. A canary in the coal mine. Add up all the spree killers in the US and they'll not break 1% of the murders. Just like the debate over automatic weapons is a canard, since they're very rarely used in murders.

The US has a murder problem. It's murder rate is four times that of it's industrialised contemporaries. Most of those murders (~75%) are done with firearms, and most of those (>75%, can't recall exactly) are done with handguns. And by someone who knows the victim closely.

The stereotype of the inner-city gangsta gunning down a gangland enemy with an automatic weapon is an outlier. And the same is true of the spree killer. As long as debates on either side center on these kinds of outliers, little will be achieved. The murder rate isn't going to be affected by open carry, since most murders aren't of strangers. And banning automatic rifles isn't going to do anything either, because it's handguns that do the dirty work.

The problem is that these details aren't sensationalist. Being gunned down by a stranger on a rampage makes the news. Being killed by a crazy relative doesn't.