The logic that they have different social conditions that place different incentives on people's behaviour. For example, Venezuela banned private gun ownership, but that is not the reason for firearm deaths falling. The reason for that is because of the economic meltdown is so bad that bullets are too expensive for even criminals:
The thing is that with easy access to powerful weapons, it is easier to implement such impulses in the US compared to other industrialized countries.
The US is not some hell hole where people have nothing to lose: for the most part it is a nice place to live (though, as with any place, it has better and worse areas). I think a lot of these incidents could be curtailed with better social conditions.
However, having a lot of weapons easily available is like having a lot of dry brush in the country: all it takes is one person's spark for things to catch on fire. Furthering the analogy, it's not that other countries don't have people who can be lit off, it's just the surrounding environment has reduced (though not eliminated) the chances of a large conflagration.
This is an answer to every single tricky political problem. If people resort to something those in power don't like - then they didn't provide good enough conditions for people to be happy and not do that.
* https://www.independent.co.uk/news/world/americas/venezuela-...
It is a control on the variables that can confound comparison so we have a more apples-to-applies situation.