Agree, but if we catch an occasional mass shooter now and then it would be worth it.The issue is, what level of mental illness or possible illness should require legal intervention in regard to gun possession or ownership. What laws are in place to allow the temporary suspension of gun possession or ownership.
We have seen a pattern of mass shootings where law enforcement was notified of possible mental illness situations but law enforcement lacked any options to intervene and suspend gun possession and ownership for a period of investigation and determination.
That would be impossible to determine, as even the most thorough psychological examinations don't always give conclusive results. There are signs though. I believe the California nightclub shooter had exhibited erratic or violent behavior in the past. But many times, someone with no history of mental illness commits such shootings, just out of the blue.