It happened Monday night at 8:40 p.m. at Pete's Pizza on the 200 block of South 60th Street.
Police say a 61-year-old driver had just returned after making several pizza deliveries when he was approached at the counter by two unknown black males.
One suspect pulled a handgun and demanded money.
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After taking the delivery money, the suspects then turned their attention to a male customer who was sitting inside the restaurant waiting for food.
The robber then placed a handgun to his side and demanded cash while a second suspect began punching and kicking the man.
A third female suspect stood by the front door as a lookout during the crime.
The trio fled the scene heading south on 60th Street with an unknown amount of cash.
Police describe the first suspect as a black male, 17 years-old and 5'7" tall with thin build. He was wearing a dark colored jacket with a gray hooded sweatshirt underneath with the hood pulled up, and light colored sweatpants, and armed with a handgun.
The second suspect is described as a black male, 17 years-old with a thin build and 5'5" tall. He was wearing a dark colored hooded jacket with the hood pulled up.
The third suspect is described as a black female, 17 years-old with a thin build and 5'4" tall. She was wearing a dark colored hooded sweatshirt, and dark colored pants.
Anyone with information on this crime is asked to call Philadelphia police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).