In not being a Church goer, I would not have been in that position. But CCW is just that, concealed. No one that I have ever met knows when they will need a legally owned, and carried handgun.
So I carry everywhere there are no metal detectors.
On our yearly visit to Sacramento, visiting two munchkins, girl 5 boy 4! Oh and their parents! I have a lock blade, razor sharp folding knife, left there, and my City stick.
Best you can do in that crap hole State.
The one and only overriding condition, in this Church shooting, not skin colour, origin, or affiliation, ISIS Etc. Their mental condition, they are all nuts!
How do you screen for that? If they are not running around frothing at the mouth, etc? My simple solution, after seeing many hundreds of these incidents, over a long lifetime. Always carry. A Glock 19 is not an Insurance policy, but it sure feels nice.