And if they have enough insight to keep their feelings and intentions covert?
This is why I believe the only current realistic (easily understood by Joe Public) solutions we have available to us is 'deal with the problem when it happens, and then improve methods for dealing with the aftermath'.
I am of the opinion that mass shooters of this sort are
usually unimaginative or disconnected enough with reality that they are unable to come up with more effective methods of mass murder and/or mayhem. Comparing school shootings to serial shooters (Beltway sniper, Ohio highway, Christopher Dorner, Eric Frein, etc) alone suggests that a lot of single event mass shooters are in it for a memorable suicide by cop.
Who was behind the Chicago Tylenol murders? Surely, methods like that are more insidious than a school shooting, if less dramatic. There are countless opportunities for people with access to specialized information (think about your water purity inspectors, for instance) to make use of, if they're feeling homicidal. The Camelford water poisoning was an
accident. Most water treatment sites have minimal security. What about a guy with a knowledge of basic mechanics who picks random vintage cars and proceeds to surreptitiously cut the brake (draining them instead of leaving a puddle, of course) lines?
And what if you have a serial killer who picks victims randomly from major metropolitan areas, waits years between victims, and uses a different method for murder every time, occasionally even looking at local crime statistics to recreate homicides in the area whose perpetrators have not been found?
My point is, there's no way to effectively prevent a canny, determined mass murderers in a large population.
And I'm not saying it's impossible to identify single event mass shooters before the fact. I'm just saying it's impossible
now. For every person who searches 'how to build a pipe bomb' on the internet, there are probably 100,000 preteen boys, 5,000 curious people, 1,000 writers, and 1 terrorist. I pulled those numbers out of my ass, but you get the picture, right?
That said, it does seem like effective therapists would be able to find a lot of the school shooters before the fact. Penetration of mental healthcare in the population and availability of competent psychologists who practice with a basis in evidence based theories is
probably shitty. Not sure if that will change any time soon.
In the end, it seems like there's just response time to incidents, and that's where guns rights peoples say 'if everyone had a gun, someone would have shot him'. I'm not convinced that a world like that wouldn't just lead to a lot of instances of friendly fire and really chaotic firefights, given the current environment. Reflexive fire in urban environments is ridiculous even when people train as teams every three months. Even if it were legal, I don't think the majority of people would carry a gun. I don't have to do any extra paperwork for a concealed carry license, and I could probably pick up a weapon tomorrow for $200 or less, but I would rather spend that money on buying new brakepads, a gym membership, or a safer bicycle helmet.