IN an eerie final Facebook post, the former US Marine who allegedly massacred 12 people in a California bar ranted about mass shootings and the "hopes and prayers" commonly offered to victims after them, according to a report.
"I hope they call me insane … (laughing emojis) wouldn't that just be a big ball of irony?" Ian David Long, 28, wrote around the time of the attack, police officials told CNN.
"Yeah … I'm insane, but the only thing you people do after these shootings is 'hopes and prayers'. or 'keep you in my thoughts' … every time … and wonder why these keep happening …"
Police told the outlet the post was made by Long, but the shooter's Facebook account or other posts haven't been previously reported, reports the New York Post.
On Wednesday night local time, Long stormed into the Borderline Bar & Grill in Thousand Oaks, about 65 kilometres north of Los Angeles, and unleashed a hail of bullets before turning the gun on himself.
Long killed 12 people, including a policeman who had rushed in to help.
It comes as one of Long's high school PE teachers recalled him lunging at her and shaking with rage.
Dominique Colell told the Los Angeles Times that Long "lunged" at her in 2008 when he was a student at Newbury Park High School.
Ms Colell, then 28, was the girls athletics coach and also disciplined the boys team.
"He started to grab at me," Ms Colell told the paper.
"He reached around and with one arm, groped my stomach. He grabbed my butt with the other arm."
The incident erupted when the coach found a mobile phone and was trying to figure out who owned it.
When Long saw Ms Colell with the device, he rushed over, yelling expletives and demanding that she hand it over.
But she refused, telling him she needed to make sure it was his, by calling the number listed under "Mum."
That's when he lunged, she said.
After that Ms Colell said she demanded Long, "Get out!" and kicked him out off the boys' team.
The next day, Long came to practice with flowers and begged to be allowed back on the team. Ms Colell refused.
Another coach to whom Long had complained questioned her decision, and another teacher told her she was "just too young and good-looking to be taken seriously," she said.
Other coaches pressured her to accept Long's apology, telling her she was ruining his future since the incident would jeopardise his Marines application.
To her regret, she gave in, she said.
When Ms Colell learned that Long, 28, was behind the massacre at a California bar, her jaw dropped, she said.
"It was shocking - but it wasn't shocking that it was him," she said.