The baggage claim area is not a gun free zone. It's outside security and literally anyone from the street could come in with a gun,
Ditto for the area beyond 'security' as all literally anyone from the street walk in with a gun, open fire at anyone attempting to stop them from entering the 'secure' area.
There are also plenty of less obvious ways to get a weapon into that area, alas for you the dotted security line only provides security theater.
everything to do with mental health care.
And that solution is... ?
They thought he was deranged, so they passed him off to local PD who got him run through whatever cheap mental health screening they use for nuts off the street and then he was set loose again.
And? The ACLU and others fought against involuntary confinement long ago and won. Today, if you can say where you are and why you are there, short of any overt acts of of violence, you aren't going to be held for very long as like it or not... even the mentally ill have the right not to be held without due process.