And unless he's a sociopath, I'd guess the odds are greater than 50-50 that he takes his own life. Then, his family has to endure their bitterness at what he's done, plus an even greater bitterness towards the vile comments hurled at him, which they will then blame for his suicide.
Unfortunately, in a moment of panic like that, as the armed guard has only seconds to decide what to do, there's zero time and zero room in the adrenaline-hyped brain to look forward to what the future may hold for you and your family if you do NOT risk your life as your job description requires.
True dat.
All of the school employees need to know what the plan is ahead of time. There is no time to process what you want/need to do without prior thinking/planning.
Unfortunately schools have become targets. If you want to stay, have a plan.