Daniel Wenzek, a 56-year old Brea resident, was arrested on suspicion of a felony assault with a deadly weapon, according to the Orange County Register.
Wenzek’s motivation is still being investigated, Lt. Kelly Carpenter said.
Among the demonstrators outside the congressman’s office were people with Temporary Protected Status, which prevents them from being deported because of natural disaster or political conditions.
Recipients are calling for the Trump administration to extend the program.
Recipients of Deferred Action, which protects undocumented immigrants who came to the U.S. in their youth, also joined the protests. Royce was not in his office at the time.
There were roughly 150 to 200 protesters at the time and the protest was peaceful, according to Carpenter.
When part of the group began to block an intersection, the police asked them to clear and the protesters complied.
It was around the time the protesters were leaving that Wenzek allegedly drove his car through the remaining crowd.
A video of the incident, posted by UNITE HERE Local 11 showed one protester slamming the hood of the car as it drove through and another jumping onto the hood.
Wenzek was arrested and later released pending further investigation.
SEIU United Workers West president David Huerta said four members and two staffers were taken to the hospital for evaluations.
Huerta emphasized the protesters had permission from the Brea Police Department and that his organization would fully comply with investigators.
“We are grateful for the bravery of officers who stopped the driver before more violence was committed, and who took the perpetrator into custody,” he said.