Relating this incident to a gun problem is like relating 9/11 to an airplane problem.
9/11: zero guns used
Oklahoma city bombing: zero guns used.
If he'd driven a rental truck as far as he could and blown it up, he'd killed far more.
I don't approve of this any more than anyone else but fact is, there have been plenty of terror attacks around the world, even in Canada, that use no firearms.
This is a mental health problem, plain and simple.