Surveillance video captured the robbery on the 6900 block of Torresdale Avenue on Feb. 5.
The video shows the suspect grabbing the woman's purse and pulling it so forcefully that she falls to the ground.
On Tuesday, police released new images of the suspect in hopes of generating tips.
Investigators say the suspect fled the scene with the woman's purse, cash, keys and cellphone.
A reward of $2,000 is being offered for information that leads to an arrest.
Anyone with information is urged to call police at 215-686-TIPS.