Police said the girl left her home around 1 a.m. on Tuesday, Nov. 10 and was walking on the 3100 block of Frankford Avenue in Kensington when she encountered a man at a Sunoco gas station.
The man offered the girl a ride to her aunt's home, police said.
The man walked the girl to his car and told her to sit inside the vehicle.
Once in the car, police said the man sexually assaulted the 14-year-old.
Authorities released surveillance video Tuesday which appears to show the suspect wearing an orange/red baseball cap.
Police say anyone who sees the suspect should not approach him and call 911.
Anyone with information about the crime or the suspect should contact Special Victims Unit at 215-685-3252.