"If it was common knowledge that there was a non-trivial number of armed people at the location in question this probably wouldn't be happening" would be more appropriate.
People committing violence choose soft targets over hard ones when they can.
People committing violence choose soft targets over hard ones when they can.
There is a better way, other countries have figured it out already.
(Edit: nevermind, I guess you’re talking about Australia and not Europe)
I'm Australian.