DeKalb police have arrested Ahmed Hussen Hassan, 23, of Chicago on charges of an armed robbery at Stop-N-Shop, 708 E. Lincoln Highway.

The robbery occurred Tuesday night, when Hassan walked into Stop-N-Shop and reportedly threatened a victim with a knife before taking an undisclosed amount of money from the register.

Hassan was spotted by an off-duty DeKalb police officer as he fled the scene. The officer was not aware that Hassan had just robbed the store, but did remember his car description, said Lt. Jim Kayes of the DeKalb Police Department.

Later that evening, when Hassan attempted to come back to DeKalb, a tollbooth operator spotted Hassan’s vehicle and contacted authorities, who stopped him at the corner of Annie Glidden Road and Lincoln Highway.

After the victim identified Hassan, police arrested the suspect.

Hassan is charged with armed robbery, burglary and unlawful use of a weapon. He remains in the DeKalb County Jail with a $50,000 bond. If convicted, Hassan could face about five years in prison because he has no previous criminal record, Kayes said.