Have we become used to or immune to mass shootings?

[DanaC]

Only disability reported to the NICS is mental illness - people who should not be sold assault weapons.

That is an awfully broad brush we're waving about there. There are many different kinds of mental illness.

In cases of mass shootings, while mental illness may be a factor it's rarely the determining factor.

You can be mentally ill or unstable without being wicked - and you can be plenty wicked without being mentally ill.