The FBI has a good paper on 'the school shooter' and what schools need to do to prevent those incidents. And there are things that can be done. Schools need risk assessment tools and plans. I've linked to it before.
There is also a workplace shooter plan, identifying who is at risk like blaming others among other things, and establishing a plan, how to get law enforcement involved and so on. I've been to conferences on 'going postal' that advise employers on how to establish such a plan.
In the latest shooting at Sooper's that might have been prevented by better educating people who are worried about family members and taking away roadblocks. For example, police have to stop shooting mentally ill people in a crisis when someone calls for help. Would you call the police to help you with your schizophrenic child knowing how often they just shoot the person?
Family members need resources and education. This one is a little loftier of a goal but we can still begin to address it.
Do you see how none of those address these kinds of shooters:
The Way We Think About Mass Shootings Ignores Many Black Victims
The article bemoans the fact these murders don't get the same press coverage. And that is a valid complaint.
That is not the school shooter, not the schizophrenic shooter, not the workplace shooter.
While they obviously need attention, and news coverage, they are a different animal. Equal attention doesn't mean they should all be lumped together into "gun violence" because that really limits the actions we need to be taking.