Investigators say the man walked into the TruMark Financial Credit Union at 1931 South Broad Street, presented a threatening note and demanded money.
The teller complied, and the man fled with an undisclosed amount of cash.
His face was captured clearly by a surveillance camera.
Police are looking for an African-American man, about 40 years old, 6 feet tall, 250 pounds with a heavy build and a salt-and-pepper beard.
He was wearing a dark colored hoodie and a black hat with a NY Knicks emblem on it.
If you recognize the man in the picture, police ask you to call 911 right away. To submit a tip by telephone, call 215.686.TIPS (8477).
You can also submit a tip anonymously online using this form.
