The ex-wife of Texas gunman Devin Kelley said he frequently displayed violent tendencies and once put a gun to her head over a speeding ticket.

Tessa Brennaman, 25, said her former husband, who killed 26 people after opening fire at the First Baptist Church in Sutherland Springs earlier this month, “had a lot of demons or hatred inside of him”.

Describing how Kelley, a former US Air Force airman, had once threatened to kill her for getting a speeding ticket, she told CBS News: “He had a gun in his holster right here and he took that gun out and he put it to my temple and he told me: ‘Do you want to die? Do you want to die?’”

Kelley had also threatened to kill her and her entire family, she added.

In 2013, the airman, then 23, admitted hitting, choking and kicking Ms Brennaman and fracturing the skull of her young son. He was sentenced to a year in a military prison over the incident.

Ms Brennaman filed for divorce shortly afterwards.

The US Air Force admitted this week that it had failed to notify federal authorities of the conviction, which would have meant Kelley was banned from purchasing the guns used in the shooting.

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After shooting 26 people dead and injuring 20 others, Kelley dropped his AR-15 rifle and fled from the church in his truck, pursued by two Sutherland Spring residents. He was later found dead in the vehicle. Investigators believe he shot himself with a handgun.

The shooting is believed to have stemmed from a domestic dispute involving Kelly and his mother-in-law, who was a member of the church community but was not present on the day of the massacre.

Less than a week before he carried out the massacre, Kelley is reported to have shown up at a Halloween event at the church acting strangely and dressed all in black.

One member of the community, Judy Green, said he was “completely distant and way out in thought”.

“He didn’t even blink – he just stared”, she said. “There was something wrong with the picture. I was thinking forward, and that was what was scaring me.”