If you're a hospital worker, then you deal with the individual in the story exactly as the other hospital workers did before the police arrived, as they always

If you're a hospital worker, then you deal with the individual in the story exactly as the other hospital workers did before the police arrived, as they always do, and nobody gets killed. If you give people guns, empower them to use them, and protect them from the legal ramifications, then stories like this are the obvious outcome.