Let’s imagine that we KNEW keeping guns out of the hands of the mentally ill was the answer to all the shootings.

To hazard a guess, I’d think those who’d already indicated that they were a danger to themselves or others.

Unfortunately, some of our shooters did not previously indicate that they were dangerous. It’s moot, of course; many states already have laws restricting gun ownership of (and including the ability to remove guns from) those classified as “dangerously mentally ill”. Texas was not one of those states. Nevada, and Florida are, but rarely enforce it.