Amid a backlash in response to a University of Wisconsin-Milwaukee student holding a Nazi sign with anti-Semitic language while protesting an Israel Independence Day event on May 6, the school, citing freedom of speech, said such action cannot be stopped.

Kristian Gresham has been described as “a 26-year-old man with a documented history of aggressive, racist and criminal behavior, demonstrated last week before a group of Jewish and pro-Israel students while holding signs that featured swastikas and a call to gas Jewish students,” according to a Change.org petition calling for his expulsion from the school, which to date has 835 signatures.

In a statement, the school administration stated that “as a public university, the University of Wisconsin-Milwaukee respects everyone’s right to free speech, even when it is speech that we disagree with.”

In two statements, university chancellor Mark Mone condemned the incident, but said the student had a right to protest.

“Many of you have expressed concern that my last campus message—which came in response to a student carrying a sign with a swastika on it during an Israeli Independence Day event on our Milwaukee campus last Monday—inadequately addressed the significant harm that it caused,” he said in a statement on Tuesday. “Please know I have heard you and acknowledge my message did not fully capture or reflect how deeply saddened, frustrated and angry I am personally, as a member of this community, that anyone would inflict such pain and fear on our Panther family. I am sorry.”

In a statement last week, Mone said, “Under the First Amendment, displaying offensive symbols, such as a swastika, to a general audience in a public space is protected akin to speech. Nevertheless, please know that we emphatically renounce such hateful symbols and do not support or condone any viewpoint that is hurtful, harmful or disparaging.”

“We are a large, urban public university that will always be a forum for the free exchange of ideas, even when those ideas are hateful or repugnant and challenge our thinking in dreadfully unsettling ways,” he said.