CHICAGO - A man who is suspected of four bank robberies in downtown Chicago pulled off a fifth heist this week, police said. The most recent theft came at a Chase Bank in the Loop just before 1:00 p.m. Monday.

"We responded to a bank robbery in progress at Chase Bank on West Jackson Boulevard at around 12:55 p.m.," said Jose Estrada of the Chicago Police Department. "We had a lone male offender." The robber escaped with an undetermined amount of cash and is still at large.

As the robber has done in his previous thefts, he wore sunglasses and a baseball cap. In a surveillance photo released on the FBI's Bandit Tracker website, the man is wearing a gray Chicago Bears hat, black sunglasses, and a black t-shirt with "ADIDAS" spelled out in bright yellow letters on the front.

The Bandit Tracker website describes the man as "white or Hispanic; approximately 5'10? to 6'0?, weighing 200-215 [pounds], and 30 years of age; stocky build; moles or tattoos on face near temples."

His other heists have all come in the past month, starting on Aug. 13. All of the banks affected are downtown.

Following the Aug. 13 theft of a Builders Bank branch, the man subsequently hit a Chase Bank branch on Aug. 17, a Chase Bank branch on Aug. 22, a Citi Bank branch on Aug. 31, and then the Chase Bank branch on Sept. 10.

According to the website, there have been 137 robberies thus far this year in Chicago, compared with 115 in all of last year.