Man walks into Texas church with Ruger AR-556 rifle, kills 26, wounds 20

It's not just a mental health issue.

Reported in Texas church shooting leaves 26 dead, including 8 members of one family.  (CNN, 11/6/2017)

Source:   New From Ruger: AR-556 Modern Sporting Rifle

(The Truth About Guns, 9/24/2014)