SAN FRANCISCO (CBS SF) — A 21-year-old San Francisco woman has been arrested for assaulting an police officer while he was riding his bike on his beat, authorities said Monday.

According to investigators, Vera Rideout was riding a skateboard northbound on 5th Street from Mission Street last Monday when she jumped off her skateboard, approached the officer from behind and, with a two handed grasp, swung the skateboard striking the officer across the back of his head.

The male officer was knocked off balance, but was able to prevent himself from falling to the ground. He dismounted apprehended Rideout who challenged him to fight as he took her into custody.

The officer’s helmet was found to have cracked in several places and it is believed that the helmet prevented him from suffering severe injury. The officer was on-duty and in full uniform when he was attacked. He was later treated and released.

Rideout was booked for assault with a deadly weapon, threats against an officer and possession of a controlled substance.

SFPD Southern Station Investigators are seeking the assistance of the public in providing any cell phone video that may have been captured during the assault.

Anyone with information is asked to contact the Southern Station Investigation Team (SIT) during business hours at 415-575-6000, anonymously at the SFPD Tip Line at 415-575-4444 or Text-a-tip to TIP411 and begin the text message with SFPD.