A jury convicted a Tennessee National Guard recruiter who opened fire inside an armory and wounded three people, rejecting his claim that he was trying to kill himself and started firing wildly when a soldier grabbed him from behind.

Authorities said Amos Patton was angry after he learned he was being removed from his job because a female soldier had accused him of sexual assault and he pulled a gun from a fanny pack and began shooting on Oct. 24, 2013. Three of his superiors were wounded in the attack.

Patton was found guilty of nine charges, including four counts of assault with a firearm with intent to commit murder. He faces at least 20 years in prison when he is sentenced May 28.

Patton showed no reaction when the verdict was read.

The jury deliberated for slightly more than two hours before reaching a verdict. Patton did not testify.

On the day of the shooting, Lt. Col Hunter Belcher told Patton about an official recommendation to remove him from his job and reduce his rank from sergeant first class, according to testimony. The meeting came after an investigation of a sexual assault complaint, investigators have said.

The jury wasn't told about sex assault allegation. Defense attorneys and prosecutors agreed to leave out the sexual assault details because it was not relevant to the actual shooting.

After the disciplinary meeting, Patton and two superiors went to his government-issued car outside the armory. They were going to drive back to Patton's office, but Patton got a bag and a fanny pack from the car, then asked to go to the bathroom.

Patton entered the armory but was told by Sgt. Maj. Christopher Crawford that he could not go into the bathroom with both items, according to testimony.

Patton then reached toward the fanny pack and pulled out a 9mm pistol. Crawford tried to restrain Patton with a bear hug and they fought. He fired six shots.

"He looked toward me, he pointed toward me and started firing," Belcher testified. He was grazed in the leg and back.

Sgt. Maj. Ricky McKenzie was hit in the foot. Maj. William J. Crawford was shot in the thigh as he went to help Christopher Crawford. The Crawfords are not related.

Patton ran outside after he was disarmed by the Crawfords. There, he came face to face with McKenzie, who pointed a gun at Patton.

"Patton says, 'Do it,'" prosecutor Mark Erskine said in closing arguments. But McKenzie did not shoot.

Moments later, Patton was subdued and later arrested.

In closing arguments, prosecutor Fred Godwin said Patton took the loaded gun and 50 extra rounds of ammunition to the armory with the goal of shooting someone if he lost his job.

"It's nothing but an ambush," Godwin said.

Defense lawyer Michael Stengel said Patton wanted to go to the bathroom with the gun to commit suicide. Patton only fired because he was being grabbed from behind and his upper arms were restrained as he was taken to the ground, Stengel said.

He noted that there were bullet fragments in a window frame, a door jamb and a ceiling tile.

"These were wild shots," Stengel said in closing arguments.

He declined to comment after the verdict. Prosecutors said they would issue a statement later.