I'll google some of the incidents and see what I can get.

However, exceptions only highlight the rules. It is still a fact: Most mass shooting happen in gun free zones.

However, Chicago is a typical case of gun control doesn't and won't work. Chicago still has the most strict gun control laws and still doesn't allow concealed carry (yet). There are lot of gun crimes before and a lot now. So it doesn't count.

Gilffords is a known exception gun-right people concedes.