I think it is time to put our cards on the table.
A mentally ill man bought a gun legally and passed an FBI check. He murdered 6 people, and seriously injured 14 more.
How could this have been prevented?
He was mentally ill and many people apparently knew about it. He should have been hospitalized, simple as that. Apparently many people were aware of his condition and did nothing about it. That is the mistake that was made. We have mandatory reporting laws on child abuse. Maybe we should have the same reporting for mentally ill people, instead of privacy laws, so that the schools, the military, and other officials would have been required to report him to authorities so they could have had him evaluated and hospitalized.