On Wednesday, a philosophy professor who was a teaching assistant at San Francisco State University between 2013 and 2015 and also taught philosophy and ethics classes at Diablo Valley College in 2015, was arrested on suspicion of using a metal bike lock to assault supporters of President Trump at a Patriot Day rally in Berkeley in April.

Videos of the incident surfaced, allowing investigators to identify Eric Clanton, 28, hooded and masked while allegedly smashing at least three Trump supporters in the head according to police, who attested that the assaults caused “significant injuries.”

Clanton is charged with three counts of suspicion of assault with a deadly weapon that isn’t a firearm and assault causing bodily injury. On Thursday, he was booked in Berkeley Jail in lieu of $200,000 bail; he was scheduled for arraignment Friday morning in Oakland.

The 4Chan website identified Clanton, according to Berkeleyside, which interviewed Berkeley Police Capt. Ed Spiller. Spiller said Clanton had been under investigation before his arrest. According to KPIX, police said catching the bike-lock attacker was such a priority that they put homicide detectives on the job. Berkeley Police Lt. Kevin Schofield said, “You’re swinging a small metal object that can absolutely cause traumatic injuries.”

Clanton’s Diablo Valley faculty page entry read, “His work in political philosophy also centers on mass incarceration and the prison system. He is currently exploring restorative justice from an anti-authoritarian perspective.” A Diablo Valley spokesman told KPIX that one of the the philosophy classes Clanton taught was “Introduction to Ethics.”

Diablo Valley spokesman Tim Leong said, “We especially at Diablo Valley College received, in fact, hundreds of calls and emails concerning the hiring, that we have someone like this in front of our class, in front of our students, potentially dangerous.”

Clanton received his M.A. in Philosophy from San Francisco State University and his B.A. in Philosophy from California State University, Bakersfield.

Video of one attack below: