The Shell Dash-In gas station at 8200 Liberty Road was the site of an armed robbery Sunday afternoon.
At about 4:47 p.m., three men wearing hoodies came into the Windsor Mill store. One had a black handgun and the others had bags for money.
One suspect placed the gun against an employee's head and made her open the cash register.
The men stole $882 and ran from the store toward Langrehr Road.
According to Elise Armacost, spokeswoman for Baltimore County police, K9 and aviation units tried to locate the suspects.
An investigation is still ongoing, she said.