A masked protester supporting transgender rights was taken into custody at the California state high school track-and-field championships over the weekend. The individual was caught on camera using a Progress Pride flag to assault another participant at the contentious event.

The individual behind the attack has been identified as 19-year-old Ethan Kroll. He was arrested on Friday and faces charges of assault with a deadly weapon other than a firearm, obstructing a public officer, and vandalism under $400. Kroll was released the following evening, according to information available on the Fresno County Sheriff’s Office website.

News of the arrest initially surfaced through local media outlets after a video of the incident, captured by Josh Fulfer, made the rounds online. Fulfer, a reporter supported by crowdfunding, was present at the protest in solidarity with “the female athletes that were having to compete against a male,” as he explained to Fresno’s Fox affiliate.

This weekend’s meet outside Fresno was the latest front line in the ongoing debate over trans athletes in female sports. In defiance of Donald Trump and his executive order, trans athlete AB Hernandez claimed gold in the girls high jump and triple jump at the California Interscholastic Federation (CIF) state finals.

‘We were out there for a couple of hours, had no incident whatsoever,’ Fulfer told Fox 26 of his protests on Friday.

After seeing the masked protester, Fulfer admittedly said something amounting to: ‘If you’re so proud of your cause, why do you have a mask on?’

Ethan Kroll is identified as the 19-year-old man booked Friday for assault with a deadly weapon other than a firearm, obstructing public officer and vandalism under $400

The arrest was first reported by local media after viral video of the incident was recorded by Josh Fulfer, a crowd-funded reporter protesting against the inclusion of a trans athlete 

‘Next thing I know, that person is darting out across the intersection and I hit ‘record’ when they’re about 10 feet away. And they started assaulting me with the flagpole through my driver’s-side window.’

Fulfer said he reached for his pepper spray at the urging of his wife and sprayed the protestor in the face.

‘That got the flagpole out of the vehicle, and then they started vandalizing the car, hitting the top of the roof of the car and the door of the car.’

After running a red light and finding a safe place to park, Fulfer said he got out to witness Clovis (California) police jumping the fence to make the arrest.

Fufler said he suffered some bruises and scrapes as a result of the attack.

Police have said an investigation is ongoing.

Daily Mail’s attempts to reach Kroll have been unsuccessful. An attorney for Kroll was not listed on the Fresno County Sheriff’s Office website. 

As for the meet, Hernandez competed under a new rule, allowing for the possibility of multiple winners in events in which she competed.

Hernandez finished the high jump with a mark of 5-foot-7 (1.7 meters), with no failed attempts. Co-winners Jillene Wetteland and Lelani Laruelle also cleared that height after each logged a failed attempt. The three shared the first-place win, smiling as they stepped together onto the podium.

Hernandez wrapped up the night with a first-place finish in the triple jump, sharing the top spot with Kira Gant Hatcher who trailed by just over a half-meter. Earlier in the afternoon, Hernandez placed second in the long jump.

The CIF announced the new policy earlier this week in response to Hernandez’s success heading into the championships. Under the policy, the federation allowed an additional student to compete and medal in the events where Hernandez qualified.

Transgender athlete AB Hernandez defied Donald Trump’s order to compete at the California Interscholastic Federation state finals in Clovis on Saturday 

Hernandez claimed tied-first place in the varsity high jump final, forcing female competitors Lelani Laruelle and Jillene Wetteland to share their spot atop the podium 

Hernandez was escorted into the stadium by an entourage of championship officials 

The two-day championship kicked off Friday in sweltering heat at a high school near Fresno. Temperatures reached the triple digits during Saturday’s finals.

The atmosphere was relatively quiet despite critics – including parents, conservative activists and President Donald Trump – calling for Hernandez to be barred from competing. Some critics wore pink bracelets and T-shirts that read, ‘Save Girls’ Sports.’

During Friday’s qualifying events, an aircraft circled above the stadium for more than an hour with a banner: ‘No Boys in Girls’ Sports!’ Two groups that oppose transgender athletes participating in women’s sports – the Independent Council on Women’s Sports and Women Are Real – took credit for flying the banner.

The federation’s rule change reflected efforts to find a middle ground in the debate over trans girls’ participation in youth sports.

‘The CIF values all of our student-athletes and we will continue to uphold our mission of providing students with the opportunity to belong, connect, and compete while complying with California law,’ the group said in a statement after announcing its rule change.

A recent AP-NORC poll found that about 7 in 10 U.S. adults think transgender female athletes should not be allowed to participate in girls and women’s sports at the high school, college or professional level. That view was shared by about 9 in 10 Republicans and roughly half of Democrats.

The federation announced the change after Trump threatened to pull federal funding from California unless it bars trans female athletes from competing on girls teams. The federation said it decided on the change before then.

The U.S. Department of Justice also said it would investigate the federation and the district that includes Hernandez’s high school to determine whether they violated federal sex discrimination law.

California law allows trans students to compete on sex-segregated sports teams consistent with their gender identity.