They are very uncommon (as in zero) where I live in the US. There are also a lot of gun owners in my community. It's hard to measure the effect of such a deterrent.

The mere fact that they're a regular happening over there says enough.

Fabs

news

Finland to open 300 shooting ranges to boost interest in national defence

kristapsk

There are never any mass shootings at gun shows or gun stores in the US where many law abiding gun owners open carry, despite there being very easy access to guns at these events. Sadly, most mass shootings take place is gun-free zones like schools where there are many defenseless victims to be found.