The incident happened on September 9 at the Citgo gas station located on the 4600 block of Lancaster Avenue.
The suspect was caught on surveillance video walking into the gas station shortly before midnight.
He immediately approaches the counter and kicks in the employees-only door.
Click here to watch the surveillance video
The suspect then pointed a gun at the clerk and demanded cash.
He got away with an unknown amount of money from the register before fleeing the scene.
Police describe the suspect as a black male, 5'8" tall with a medium build. He was wearing a black hooded sweatshirt, dark colored pants, baseball cap, blue scarf covering his face, and armed with a handgun.
Anyone with information is asked to call police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).
You can also submit an anonymous tip online at PhillyPolice.com.