The robbery occurred behind the Key Food Mart, located at 325 W. Rosemary St., at 9:23 a.m., police reports state.
The victim, an employee of UNC Hospitals, reportedly had $500 in cash stolen from her as she neared the store.
Lt. Jeri Cole of the Chapel Hill Police Department said the woman was on her way to purchase a money order from the Key Food Mart at the time of the incident.
Reports state that the suspect approached the victim in the alley near the Gotham nightclub and placed a sharp object against her back to obtain the victim's money.
Khalid Mahmoud, manager of the Key Food Mart, said the victim then entered the store and asked him to call the police.
Cole said this kind of crime is unusual for the area around the Key Food Mart and that most calls to police pertain to loitering or minor disturbances.
"We usually don't have robberies in that area," Cole said.
Mahmoud said the majority of problems spring from complaints about panhandling in the parking lot, adding, "there is not much crime."
"Chapel Hill is very peaceful," he said. "The police are in and out."
