“From the video that’s being shown, you can’t see if it’s an officer that pulled [the protestor] to the ground or if he tripped,” said Sgt. Sean Swain of the Cumberland County Sheriff’s Office, according to the Wall Street Journal. He also said he isn’t sure the police directly saw the incident to know who threw the punch.

The punch was caught on video and happened as protestors were being led out of an arena in Fayetteville, N.C. As they ascended the arena’s steps, an attendee of the Trump rally, wearing a ponytail and a cowboy hat, walked over and struck one of the protestors directly in the face. Officers immediately grabbed and subdued the protestor before escorting him outside. There’s no video evidence that police reprimanded the assailant.

The aggressive incident is one of many that have happened at Trump rallies, and protestors are regularly asked to be escorted out by the candidate himself. That is done by either campaign security or local police force, not by Secret Service. Trump or other candidates can request people be taken out of rallies since they are considered private, not public, events.

The Fayetteville incident shows how this dynamic can become fraught in a charged political environment. The local sheriff said the investigative team is looking into what went down and criminal investigators are trying to determine the identity of the assailant. Despite the lack of clarity, Sgt. Swain continued to defend his police force, saying that they “did what the Secret Service asked us to do and separate everybody.”