Dramatic surveillance video shows the half-minute of terror when two armed robbers launched a takeover-style robbery of a southwest Atlanta convenience store.

It was after 10:30 Monday night when two suspects, described as black males in Halloween masks, entered the Donnelly Food Store at 1294 Donnelly Avenue.

The clerk behind the register was on her cell phone and looked up to see one man leaping over the counter to start grabbing wads of cash from the register. The second man stuck a .45 in her face, looking around the store.

Atlanta Police Sgt. Warren Pickard says the robbery quickly escalated to violence.

"We think that at some point, one of the store owners entered the shopping area from the back," Pickard explains. “And it might have startled the shooter. He fired one shot, striking the store owner in the chest."

The victim, nicknamed by neighbors as "Papa" or "Dad," was taken to Grady Hospital in critical condition.

"We're concerned about all crime, but when you enter a store at peak shopping hours, really just put other people's personal health in jeopardy, brandishing a weapon, firing shots--it's just conduct we can't accept," Pickard says.

He adds that while both robbers were masked, police hope someone will recognize them from their mannerisms or distinctive clothing.

Crime Stoppers is offering a $2,000 reward in the case, allowing tipsters to remain anonymous at (404) 577-TIPS (8477).

"We just need some help to solve this heinous crime," says Sgt. Pickard.