A conservative speaker was assaulted Thursday at the University of Missouri-Kansas City after a student sprayed him with what was feared to be a toxic substance.

Commentator Michael Knowles was presenting the conservative side of the transgender debate in a speech titled “Men Are Not Women” when he was attacked, The Hill reported.

In a video of the incident, police are shown tackling the assailant and they appeared to use a stun gun in the process. The student was then arrested.

Police said student Gerard Dabu sprayed Knowles with what was later found to be a mixture lavender oil and other nontoxic household liquids.

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“A UMKC student identified as Gerard G. Dabu has been charged with peace disturbance — disturbing schools or lawful assemblies; assault on law enforcement; and property damage. Dabu was arrested Thursday night and released on bond. Today, Dabu also has been charged with assault and resisting arrest of law enforcement and in the discharge of their duties,” the university said in a statement, according to The Wrap .

UMKC Chancellor C. Mauli Agrawal, in an email to students, sought to explain the police reaction.

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“Police had no choice but to react as if the substance was an immediate danger. Tests later revealed the substance to be lavender oil and some other non-toxic household liquids. A campus disciplinary investigation is under way,” he wrote in the email.

Knowles said that his freedom to present his opinion was abridged from the start of his presentation on the campus.

“From the very beginning, a loud contingent of leftist students shouted relentlessly in an attempt to drown out my speech. After some time, they stood up to leave. At that point, a masked assailant approached out of my periphery and shot an odorous, strangely colored liquid at me, at which point the police tackled and arrested him,” Knowles later said in a statement.

“At first I thought this liquid might be some sort of paint. I was later told it was bleach, then later still told it was a non-toxic concoction that merely resembled a dangerous chemical,” he said.

Knowles said that the point of the incident should resonate with conservatives.

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“In any case, the message was clear: what happened last night was a warning to conservatives on campus that unless they shut up and kowtow to leftist orthodoxy, they will be silenced, intimidated, and assaulted,” he wrote.

Agrawal later issued a fuller public statement to the campus community.

“A student group brought a speaker to campus — a speaker whose professed opinions do not align with our commitment to diversity and inclusion and our goal of providing a welcoming environment for all people, particularly our LGBT community. Upon learning of this speaker’s visit, members of our UMKC community responded in the best way — by organizing and conducting a counter-event across campus Thursday afternoon focused on positive messages about diversity and inclusion,” he said.

“Then, unfortunately, some others crossed a line. UMKC must maintain a safe environment in which all points of view, even extreme ones, are allowed to be heard.”

The statement did little to satisfy Knowles, who said that the chancellor “not only did not apologize but in fact smeared me as some form of bigot.”

“Chancellor C. Mauli Agrawal is a disgrace to higher education. The assailant as well as the students who screamed throughout the lecture should be expelled from the university, and the assailant should be prosecuted to the fullest extent of the law. Enough is enough,” he said.

Knowles had been at the campus to speak to the Young Americans for Freedom, a conservative student group.

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