70-year-old woman stabbed in back while walking to pharmacy

A 70-year-old Brooklyn woman was stabbed in the back while walking to pick up medicine from the pharmacy down the block from her home last Wednesday.
The attack left 70-year-old Lin Mei Fang in the hospital in need of surgery because of where she was stabbed.  
“Suddenly somebody ran into her and bumped her around the back. At first, she thought that person was just running really fast and bumped her, so her shoulder hurt and then she felt her back and there was blood,” said Karen Lin, Fang’s granddaughter. 
Lin says her grandmother quickly walked a block home, made it in the door and started screaming for help. 
Police visited their home Thursday to try to put together a suspect's description.
Lin says there are no leads yet, but the family is holding out hope.
“We just want to know who it is doing this so that we know for sure he is not out there to attack another person or my grandma again," said Lin.