The video shows the man entering a Ross store at Serramonte Plaza shortly after the incident.
Police say the victim was entering a bathroom in an office and medical building across the street from the store when the man pushed her inside and abused her.
Detectives think the man was accompanying an elderly Asian woman for an appointment.
"Our best guess at this point is that he was probably waiting for whomever he went to that office with, for her to finish her appointment, and he was killing time," Detective Katie Scoles said.
Daly City police say the man is Asian, in his late teens or early 20s.
Several people reported seeing him in the area because he had a peculiar walk and was wearing an army green nylon jacket with a fur lined hood. He reportedly drove away in a small gray car.
