Piers -- just like any other gun control advocate -- tries to use the illogical correlation = causation argument. However, if anybody ever went through high school/college, you would know that philosophically, you can't really get solutions from that logic.
And what's even more funny, is that there is absolutely no evidence even correlating less guns to equaling less crime. In fact, that argument works much better for gun owners. In fact, there's so much correlating evidence locally, nationally, and worldwide, that it's pretty safe to say more guns = less crime.
And to top it all off, even if there was no clear solution to less crime, it doesn't matter because American citizens are constitutionally required to own guns for when the going gets rough.