The first robbery happened back on December 14 at the Dunkin' Donuts located on the 5900 block of Rising Sun Avenue.
The suspect walked into the restaurant at 5:45 p.m., armed with a handgun and handed the clerk a demand note which said: "Empty the register or you'll get shot."
He got away with an unknown amount of cash before fleeing the scene.
VIDEO: Click here to watch the surveillance video
The robber then struck two more times - first on January 4 at the Burger King on the 5800 block of Castor Avenue and again on January 20 at the McDonald's on the 5400 block of Oxford Avenue.
Each time, he threatened the clerk with a handgun and passed on a demand note.
Police describe the suspect as a black male, 40 years-old, 5'8"-6'0" tall with a dark complexion and possibly scars on his face. He was wearing a black jacket, black hat and jeans.
If you see this suspect do not approach him, contact 911 immediately.
Anyone with information on this robbery is asked to call police at 215.686.TIPS (8477) or text a tip to PPD TIP or 773847.
Tips will remain confidential.