Although if you consider societies like Switzerland which are heavily armed but dont have a guns culture and dont appear to have the mental health issues or other issues which translate into motive like in the US they dont have an issue with massacres or spree killing. I think the Swiss have some philosophy that all adults are more or less considered enlisted men and women and are not permitted to be a particular distance from an assault rifle at all times. That is something like a US militiaman's wet dream but the difference is there isnt a paranoid or impulsive/compulsive culture or whatever it is which is triggering Americans to engage in spree killing.
In the UK the last two spree killings were completed without assault rifles and the weapons laws in the UK are very tight, very tight indeed. In Dunblane the target was children in a kindergarden too and the children's carers, it was rumoured at the time that the guy could have been a peadophile but it never was reported completely, which I also think is a difference in reporting coverage culture too.