26-year-old Amber Long was shot after she refused to give up her purse to three men who attacked her and her mother in Northern Liberties.
The Fraternal Order of Police announced Monday it will double its reward from $10,000 to $20,000 if the information is received by midnight this Sunday.
In addition, The Citizens Crime Commission posted $7,000 and the City of Philadelphia posted $20,000, bringing the reward total to $47,000.
Video of the crime shows the two suspects approach 26-year-old Amber Long and her mother as the women walked along the 900 block of North Front Street Sunday night.
The suspects grabbed the women's purses, and the video stops just short of when Long was fatally shot.
Police say the suspects were driving a newer model dark-colored four door Chevrolet Impala.
Prior to the shooting, the same car was caught on camera turning into a parking lot at Brown and Front streets, and then coming out of the lot. A short time later Amber and her mother walked by the parking lot.
Police believe the suspects may have been watching the women before the attack.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.