Helen Canafax was in the 600 block of Folsom Street on April 10 when a man took her purse and knocked her to the ground, police said. She sustained serious injuries in the fall and died on April 26.
Police described Canafax as a popular and generous woman who often gave money to the homeless.
The suspect is described as a black man between 35 and 40 years old, weighing 180 pounds. He was wearing a gray beanie-style cap, a red or black sweatshirt and dark-colored pants.
Anyone with information regarding the case is asked to call homicide inspectors Richard Martin or John Cleary at (415) 553-1145 or the confidential tip line at (415) 575-4444.