This boy had a history of aggressive behavior. Enough to expell him. Enough to where his classmates expected this. His mother passed away and he was depressed. Another family brings him into his home. He brought his rifle and was asked to keep it locked and let him keep the keys.
My concern is (and this is hindsight as it usually is), should he have been left with the keys considering he was in an emotionally unstable state and had reports of aggressive behavior. I'm not blaming them. They stepped in and opened their home when he needed someone the most. But, in terms of the rifle and keys, What would you have done in a similar situation?
The issue for me is making the schools inpenetrable to shooters. Technology, scanning, concrete barriers, bulletproof glass, beefed up and armed security details doing rounds. All of these would have made it irrelevant where the gun was kept and who had the keys.