"The manager tells her, 'I'll be glad to help you, you just need to go up front,' and for whatever reason she took it upon herself to assault the manager," Santa Ana police Cpl. Anthony Bertagna told KABC.
The video shows the suspect, dressed in a light T-shirt, putting her hands around the manager’s neck and slamming her head into a drink machine.
Later in the video, a man wearing a gray hoodie comes through the same back entrance and escorts the suspect out of the restaurant.
The restaurant manager said the suspect did not seem intoxicated or impaired, but was just angry, KNTV reported.
"There is no reason that any employee at any business should be assaulted by a patron, much less over not getting enough ketchup," Bertagna told told KABC.
Police are searching for the suspect, Bertagna told the television station.