It is easy to blame the NRA but it seems to be a cultural problem. Instead of going and getting drunk and getting in a fight anyone with a grievance gets a gun and shoots up his school,church,workplace. Note, the shooters are invariably male.
There is an epidemic of knife crime in London at the moment. There is a stabbing virtually every day. There was a similar situation in Glasgow a few years ago but the police and authorities got to grips with it and now stabbings are very rare. The Metropolitan police in London have approached their Glasgow counterparts for help in combatting the problem.
The love of guns seems to be so ingrained in the American Psyche that it will be difficult to eradicate but with the will I'm sure it can be done although it will probably take a generation or more.