Police have arrested a man suspected of assaulting pro-Palestinian demonstrators in a violent attack at the University of California, Los Angeles, last month.

In late April, a group of masked people marched on to the campus at night and attacked a Gaza solidarity encampment. They threw fireworks, beat students, and attacked staff and student journalists while law enforcement and campus-hired security guards failed to intervene for hours.

Related: Why is New York University making protesters watch The Simpsons as punishment?

The attack caused outrage and sparked fierce criticism of the university, its leader and the campus police department.

Edan On was taken into custody by UCLA police on Thursday on a felony charge – what appears to be the first arrest of a member of the group involved in the attack. The 18-year-old is currently being held in a Los Angeles jail on $30,000 bail, according to jail records.

On was first identified by CNN. Videos appear to show On, whom CNN described as a high school senior, wearing a white mask and hoodie throwing objects into the encampment and assaulting pro-Palestinian demonstrators with a wooden pole. The outlet reported that his mother had bragged about his role in the attack on Facebook, but later denied that he had been present.

UCLA police said in a statement to several media outlets that it had used some of the videos shared by media in their investigation.

“UCLA police department detectives conducted an investigation that included interviewing victims, speaking with witnesses, and reviewing security camera footage and publicly available videos from members of the public and the media,” the department said.

Police have not specifically named On, though the description they provided is consistent with jail records. The department has said it is “committed to investigating” all violence reported on campus during the protests and counter-protests and identifying perpetrators.

Meanwhile, UCLA continues to grapple with the protests and their aftermath. Police dismantled the pro-Palestinian encampment following the violent attack and arrested hundreds of people. Protesters established a new encampment on Thursday – as the UCLA chancellor joined other campus leaders to testify before Congress about the demonstrations – which police quickly cleared.

In the tense three-hour-long session, House Republicans clashed with the president of Northwestern University over his handling of a protest community, but largely spared UCLA’s chancellor, Gene Block. Ilhan Omar, the progressive Minnesota representative, however, was critical of Block and said he could have prevented the violent attack on protesters.

“You should be ashamed for letting a peaceful protest gathering get hijacked by an angry mob,” she said.

Next week, some university workers will go on strike over the crackdown on Gaza protests. The union for academic workers has initiated a rolling strike across University of California campuses in protest against the university system’s response to pro-Palestinian demonstrations. The strike began at UC Santa Cruz this week and will spread to UCLA and UC Davis on Tuesday.