RAW VIDEO: Brutal attack in SF caught on camera
The surveillance video shows a hooded man pounding his victim's face repeatedly, continuing on even after she collapsed to the ground.
Austin Allen says this could have happened to her.
"He said something beginning with, 'Hey girls,' in a raspy voice," Allen said.
RELATED: San Francisco police release sketch of man accused of punching woman
Around 2:30 a.m. Aug. 20, Allen and her friend returned to Clay Street after a night out. Allen says the suspect in a sketch darted after them.
"We managed to get in the gate and lock it behind us before he managed to get there," Allen said,
For nearly an hour, both women huddled in the apartment. Her friend called police twice.
"Every car we heard, I was like, 'that's the cops right, that's the cops right,' because I knew if he didn't get us he could do something to someone else," Allen said,
Finally, the man walked away and Allen went home. Seventeen hours later, and just a block away the attack happened.
"My blood went cold when I saw that surveillance video, he was wearing the exact same outfit, he had the same build. Then when I saw the sketch of him, I knew it was completely him," Allen said.
Allen immediately called the San Francisco police tip line.
The police released a statement that reads in part, "We are looking into the possibility of a second victim. Investigators from Northern station will follow up."
ABC7 News canvassed Lafayette Park Saturday asking if people recognized a sketch of the suspect. No one did.
"I know a lot of people in the park, but I've never seen him," said one woman.
Allen wishes her friend's calls to police had led to a different outcome.
"I feel so bad for that woman," Allen said. She plans to carry pepper spray with her from now on.