Sgt. Dionisio Garza was a decorated soldier who served two tours in Afghanistan.

But on May 29, 2016, the 25-year-old Rancho Cucamonga native went from Army hero to mass shooter.

Garza broke into a Houston auto shop on May 28, 2016, and spent the night there. The next day, he fired 212 rounds, killing one man and injuring six other people before he was shot and killed by police.

Now, his mother, Michelle Garza, is speaking out about the toll post-traumatic stress disorder can take on veterans like her son.

“Something inside him took him right back there. He was back in war, right back in Afghanistan,” she said. “I saw him go from 0 to 100 in probably three days.”

Garza said she thinks families of veterans are not given the support necessary to care for their loved ones, who are sometimes changed by the experience of being in war.

Even one of the victims’ mothers understands how difficult it can be to care for a veteran, Garza said.

“One of the moms [of the victims] reached out to me. Her son was military. She didn’t blame him for her son being shot,” Garza said. “I found comfort being around people who understand veterans, that don’t look at my son like a monster.”

Garza added that she feels for the families that were affected by her son’s actions, and she feels guilt that her son hurt others.

“He was a great brother and great uncle and he loved this country,” Michelle Garza said. “I felt so bad cause we were so close, and I had no idea… He must’ve just snapped. It’s just not who he was. I feel so bad.”

Garza is far from alone in suffering from PTSD.

Approximately 800,000 people have served in Afghanistan, and the chances of developing PTSD are as high as one in five for soldiers who served in post-9/11 wars, according to the U.S. Department of Veterans Affairs.

The Costs of War Project found four times as many troops die by suicide than in combat.