He said the victim was targeted and the shooting was an isolated incident.
"The shooting had to do with the man who was the victim, not the ATM or the area," Thomason said.
He said the crime, which occurred at about 9:15 a.m. outside a Bank of America branch at 5148 Broadway, "is not something the general public should be worried about" in terms of doing business at the bank or at the shopping center.
The shooting victim, a 28-year-old man, was at the ATM when then suspect walked up to him and shot him in the back, Thomason said.
The suspect, described as a white man about 5 feet 9 inches tall and 180 pounds, ran away afterward.
No words were exchanged and no money was taken, Thomason said.
He said the victim is still in critical condition at Highland Hospital but was able to talk to police shortly after he was shot. Investigators will interview him a second time later today.
"We're following up on leads and hope to identify the suspect soon," Thomason said.
He said he could not yet discuss a possible motive for the shooting.