Tessa Brennaman, 26, was married to the deceased attacker from April 2011 to October 2012, and told Inside Edition that Kelley had "demons" and a violent streak.
"He just had a lot of demons or hatred inside of him," Brennaman said.
Brennaman also said he had threatened to kill her on multiple occasions, as well as her family. She recalled one of these threats, which came after Kelley got a speeding ticket.
"He had a gun in his holster right here, and he took that gun out," Brennaman said. "He put it to my temple and he told me, 'Do you want to die? Do you want to die?'"
Kelley, who was a member of the Air Force, plead guilty to assaulting Brennaman and her son from a previous marriage. He admitted to hitting, choking, kicking and pulling Brennaman's hair. He also fracturing the young boy's skull.
Kelley served one year in military prison for his actions and was discharged from the Air Force for bad conduct.
This offense should have made it impossible for Kelley to purchase the gun he used to kill 26 people and injure 20 others at the First Baptist Church in Sutherland Springs. However, the Air Force forgot to submit the conviction to the FBI. This cause no red flags to come up when Kelley purchased the weapon, a Ruger AR-556 semi-automatic rifle.