That has been mentioned, and probably will not lessen the motivation of these terrorists groups...
The attackers were rank amateurs who even left the scene in the same car they arrived in, but still had no trouble getting the weapons....
All countries need to think about security against this type of attack, restricting access to weapons, and good intelligence networks are things that will help..
In the Soviet era they were very good at spying,,, like China, Russia has a lot of cameras with facial recognition software everywhere....
The US even tipped Russia off about the possibility of a threat,
What investigations did Russian intelligence do?
Do the Russians have any idea who owns military style assault weapons within their country, or if any other terrorist groups exist?
Putin's lame attempt to blame Ukraine hasn't fooled anyone who counts in Russia....
Not only is the folly in Ukraine reducing living standards, and costing many Russian lives, it seems to be impacting on the ability of the Russian state to protect its own citizens within Russia.