At approximately 12:50 a.m. Monday, police say they think the suspect used a handgun to steal $400 from a Subway restaurant on Washington Street at Garland near the Chicago Cultural Center in the Loop.
Several similar robberies have been reported all over the city, and police say that the same suspect could be to blame for all of them.
At least 12 different convenience stores and fast-food restaurants have been targeted in recent weeks -- all on Chicago's North Side. Most of the robberies happened between 11:30 p.m. and 2:15 a.m.
"I'm just worrying. This is downtown. You would think downtown is safe, but it's not safe anymore. For those that open and close stores, it's dangerous," said employee Latasha Payne, who works at the Subway that was robbed Monday.
The store has surveillance cameras, but some workers said they weren't sure what those cameras actually caught on video.
Chicago police have released surveillance photos of the suspect.
Police reports and alerts for the 18th and 19th districts say the businesses might have been held up by the same man between the ages of 22 and 40, wearing a dark, hooded sweatshirt, and in some incidents, a black knit cap.
The height and weight description for the suspect is vague.
Police say the suspect uses a gun to get the cash, but no one has been hurt in any of the robberies.
Also among the targeted stores is a Dunkin Donuts in the 300-block of West Chicago Avenue, where some customers, nearby residents and workers said they were worried.
"Makes you feel a little uneasy, and you should feel safe going into places around here, whether it's late at night or early in the morning," said customer Steve Stewart.
Chicago police have issued an alert warning businesses, especially those that are open late and early in the morning, to watch out for the suspect.