A 25-year-old Army veteran allegedly suffering from PTSD has been identified as the suspect in Sunday's mass shooting in Houston.

Dionisio Garza III from San Bernardino County, California, has been named as the man behind the gun attack that left two people dead and six wounded.

He served four tours of duty in Afghanistan and was discharged from active duty in 2014, and doesn't appear to have a criminal history.

Army veteran Dionisio Garza III from San Bernardino County, California, has been named as the man behind the gun attack that left two people dead and six wounded in a Houston suburb on Sunday

He served four tours of duty in Afghanistan and was discharged from active duty in 2014, and doesn't appear to have a criminal history. But his father believed he may have been suffering from PTSD

Reports suggest he went on a rampage with a high-powered AR15 rifle and shot at bystanders before police gunned him down.

Pictures from the scene also show police patrol cars riddled with bullet holes.

He killed 56-year-old Eugene Linscomb and critically injured father Byron Wilson, who police say was trying to fight back and stop the deadly attack.

Authorities said Wilson had a concealed carry permit and fired at the suspect. He was shot three times in the process.

He is expected to survive.

Although no motive has been given, the veteran has recently expressed anti-government sentiments, according to KHOU.

His father told Click 2 Houston: 'We have not received confirmation, but I strongly suspect. I really believe this is a PTSD thing.

'On the internet he met some people or some people that believed like him.'

His father added that he decided to move to Houston to meet others who thought the United States was on the brink of collapse.

Byron Wilson (pictured with his wife and son) was a Good Samaritan who fought back against the suspect in a bid to stop the shooting

Reports suggest he went on a rampage with a high-powered AR15 rifle and shot at bystanders before police gunned him down. Pictures from the scene also show police patrol cars riddled with bullet holes

A car crashed into a boat near the gas station where the deadly shooting took place on Sunday

'He was rambling off about the economy collapsing, you know,' his father added.'And that something was going to happen by Monday, that kind of stuff. Of course you look back now and there were signs.'

He last spoke to his son on Saturday and could sense that something was wrong.

In 2013, a woman believed to be Garza's mother wrote on Facebook that she had spoken her son on the phone.

He told her that five of his fellow troops had died in Afghanistan over the weekend.

Reports suggested he left a military backpack at the scene filled with personal papers, documents and bullets.

One bullet hit a gas pump, sparking a fire. Dozens of cars were hit by stray bullets, narrowly missing drivers who were passing through the quiet residential area

Police returned to the scene to retrieve it on Monday. The SWAT team are said to have detonated it next to the gas station which burst into flames after the attack.

Gunshots were first heard at 10.15am in west Houston, Texas, on Sunday.

When officers arrived, the suspect turned their fire to the police and began showering bullets, seemingly at random, across the streets.

One bullet hit a gas pump, sparking a fire. Dozens of cars were hit by stray bullets, narrowly missing drivers who were passing through the quiet residential area.

At 12.30pm, Linscomb was shot dead in his car as a bullet burst through the window.

During the shooting, two officers were shot - one in the hand and one in his body but survived thanks to his bulletproof vest.

Another three civilians were also shot and wounded. All of them are expected to survive.

The suburban street where the attack took place was blocked off for most of Sunday as police investigated what happened

There were initial reports of two gunmen, but police later confirmed that Wilson was a Good Samaritan who was fighting back.

He was wounded but is expected to survive.

Garza is even believed to have fired at a police helicopter.

One motorist showed how a bullet burst through his passenger window, blew through two seats and out another window - as he sat in the driver's seat.