SAN FRANCISCO—On Saturday, September 5, police arrested a suspect in relation to the Critical Mass incident that occurred last month.

Ian Hespelt, 39, was arrested outside AT&T Park, where a Billy Joel concert was taking place. An officer on bike patrol spotted a man that matched the suspects description, including his handlebar mustache. Hespelt is stated to be an employee at Macy’s. According to reports, those who know Hespelt were surprised by his arrest, noting that he is not a violent person.

Hespelt is under suspicion of felony assault with a deadly weapon, vandalism, false imprisonment, malicioulsy and willfully throwing a substance at a vehicle, and a misdemeanor suspicion of inciting a crowd to riot. The damage done to the zipcar is estimated at around $2,000.

The incident in question occurred on August 28 at a Critical Mass Event, that occurs on Fridays at the end of every month. The event promotes awareness of bicyclists and the safety of cyclists riding with cars. Around 8:16 p.m., a video was recorded of cyclists crossing multiple lanes of traffic and getting into an altercation with a zipcar driver.

Hespelt is believed to be the suspect who is seen getting angry with a zipcar driver after stopping and blocking traffic. Although Hespelt is not the only cyclist recorded antagonizing the zipcar driver, he is the only person who is seen slamming his bike on top of the vehicle. He also takes out a U-Lock and uses it to repeatedly strike the car.

The driver of the zipcar moves  around the crowd of angry cyclists, but did not immediately report the incident to police. The female victim later spoke to police and helped identify the cyclist who attacked the zipcar with the U-Lock.

This is still an ongoing investigation and police are asking anyone with information relevant to the case to please contact the San Francisco Police Department at (415) 575-4444.