SAN ANTONIO -- A driver confronted in a convenience store parking lot quickly turns to a man fighting for his life Monday morning.

Police said the man was shot over a simple mistake. One that snowballed into the arrest of David Lilburn Johnson. He is facing a charge of aggravated assault with a deadly weapon.

Police said the 62-year-old was backing his vehicle out of a convenience store parking lot when he nearly hit the victim and his family at the gas pumps. A preliminary police report shows Johnson's rear sensors detected the family. He stopped.

It happened before 9:30 p.m. Sunday at a Valero on the frontage road in the 10400 block of I-35.

The reported victim, 32, confronted the driver and investigators said the two had a very heated exchange.

Police said Johnson told the victim he had a gun. Johnson said the victim lunged at him through the passenger's side window. Investigators said he shot the man in the neck once.

The victim was taken to SAMMC with a critical injury in unstable condition.