SAN ANTONIO -- A clerk was found dead in a video game store on the city's North Side Monday afternoon.

Managers said a co-worker found Amber Belken, 25, at the EB Games store in the 7300 block of San Pedro Avenue.

Police said they are investigating the incident as a robbery - homicide.

Police said a witness saw the victim entering the store alone around 9 a.m.

Police said they believe she was preparing the store for its opening at 10 a.m. when she encountered her killer.

Police said they don't know if the killer was inside or if the victim let the person in.

Both doors to the store were locked when managers arrived to check on the employee, managers said.

The managers had been trying to contact the woman, managers said.

When the manager failed to reach her by phone, they went to the store and found her dead just after 2 p.m., managers said.

Customers said the store didn't open Monday.

Police said they believe robbery appears to be the motive of the killing because cash was missing from the register.

Police are asking anyone that was in the area between 9 a.m. and 10 a.m. to contact investigators at (210) 207-7635 if they have any information.