The world is full of crazy people, as long as humans have working thumbs we will find a way to kill each other. More or less guns has nothing to do with people killing each other.
Here are two stories I found very quickly about people killing people without the use of guns in countries where the citizens are not allow to own guns. I guess they better get some better regulations on knives.
http://www.nytimes.com/2010/05/01/wo...a/01china.html
http://www.cnn.com/2009/WORLD/europe...ack/index.html