Updated

An Army veteran who served in Afghanistan has been identified as the gunman in a deadly shooting at a Houston auto detailing shop over the weekend.

The shooter's identity has not been made public, but multiple local news outlets reported his name as Dionisio Garza III, 25, of San Bernardino County, Calif.

KTRK reported that investigators identified Garza as the shooter after his personal papers, including his birth certificate and military discharge record, were found in a backpack near the scene Monday. According to the station, Garza's record shows that he was discharged in 2014 after attaining the rank of sergeant.

Garza also received several awards, including the Afghanistan Campaign Medal with two campaign stars and the Army Achievement Medal.

It was not immediately clear how or why investigators failed to collect the backpack from the scene after almost 24 hours.

Garza's father told KPRC that he suspected his son suffered from post-traumatic stress disorder, and his behavior had grown increasingly erratic in recent months.

"You know he was rambling off about the economy collapsing, you know," the man said. "And that something was going to happen by Monday, that kind of stuff. Of course you look back now and there were signs. There were signs."

Garza's stepmother told ABC News that she also believed her stepson was suffering from PTSD.

"He did two tours in Afghanistan. I think he was proud to be in the military, but I know he went through a lot," she said. "I don't think he ever came back the same."

The Sunday morning shooting caused panic in a normally quiet neighborhood in West Houston. One person, identified as 56-year-old Eugene Linscomb, was killed and six others were wounded, including two law enforcement officers.

One of the other injured victims, 30-year-old Byron Wilson, has officially been ruled out as a suspect after authorities determined he shot at Garza with a gun he was licensed to carry.

The gunman was killed by a SWAT officer about an hour after the shooting began.

The Associated Press contributed to this report.