The Bexar County Sheriff's Office is looking into a couple of armed robberies to find out whether they're related. Deputies responded shortly after 8 p.m. Wednesday to a robbery in progress at the Dollar General on Tarrasa at Walzem Road. A masked man pulled a gun on the store clerk, demanded cash and cigarettes, and then ran away. Half an hour later, another armed robbery happened at the Dollar General on Independence Avenue at Judson. Deputies are wondering if the same suspect is responsible for both robberies.