SAN FRANCISCO (KRON) — San Francisco police are investigating a robbery and assault that took place at a Richmond District bicycle shop.

It all happened very fast, according to the manager who was assaulted. In less than 10 seconds, the video shows a man walking into the San Francisco bike shop and steal a $1,500 mountain bike. And, on the way out, the suspect punched Anson Vaughan, the shop manager, knocking him back.

“I just tried to intervene and stop him from going anywhere further,” Vaughan said. “He went and punched me in the shoulder. I think he was going for my head but he nailed me right in the shoulder.”

The suspect took off westbound, according to police. A neighbor followed him for a few blocks, but he got away.