“…officers went to his house, he was somewhat irate, acting a little irrationally…and mental health specialists who met with him, talked to him, and cleared him, didn’t feel he was qualified to be taken under 5150.”
— Read on www.zerohedge.com/news/2018-11-08/12-killed-mass-shooting-california-country-bar

Another one they knew about, I see a trend here