Tony Foltz, 24, who is a third year law student, was hit early Sunday morning along the Ben Franklin Parkway.
Investigators say the person they want to question lives in Philadelphia, but is not a native. No other details were made available.
On Monday, police said they believed they had found the car that hit Foltz. A white Subaru was towed from the 4100 block of Ridge Avenue in East Falls. On Tuesday that car was parked at the Accident Investigation Unit.
Foltz is still fighting for his life, in a medically induced coma at Hahnneman University Hospital. He is suffering from a fracture to the right side of his skull and has a broken tibia and fibula among other internal injuries.
On Monday Foltz's father, Richard, made a plea for the driver to surrender to authorities.
"We understand somebody could make a poor decision. We'd love for a person to come forward so we could understand what happened."
Anyone with information is asked to call Philadelphia Police at 215-686-TIPS.
