There is nothing wrong with the law in this case.
She attacked them with deadly force, they defended themselves with deadly force.
What was unnecessary was HER actions.
EGGSactly Batman!
I am dead set against some of the crap cops call law enforcement that ends up killing innocent people like Bang Bang Shoot'em Up No-Knock Rambo raids. I think cops who kill some innocent person in those type raids should be flogged to death.
However if you are going to charge into Police HQ and wave a gun around then if you get shot well too bad. The cops did not ask you to come there and put people in danger. And if you are suffering from some metal illness well it is not the job of the Cops to understand your pain when you are waving a gun around. That was the job of the medical professionals and apparently they did it wrong.