The president of California State University, Fresno has launched an investigation into the professor who tweeted that “Trump must hang” and that Republicans should be executed for each immigrant deported.

“While Fresno State is committed to state and federal constitutional rights of free speech, the content of statements by Dr. [Lars] Maischak warrants further review and consideration,” said Joseph I. Castro, president of Fresno State, in a statement tweeted by the university. “The review of these and any other statements will be conducted in the context of rights of free expression, but also for potential direct threats of violence that may violate the law.”

A Fresno State spokesperson also disavowed the tweets Friday, after The Daily Caller News Foundation broke the story.

“Our primary concern is for the safety of our students and with providing a conducive learning environment,” continued Castro. “We acknowledge that our faculty have an obligation to establish and maintain ethical and professional conduct, inside and outside of the classroom.”

“The University is taking this matter seriously and handling it in accordance with applicable law and policy, as well as our traditions of academic freedom and the requirements of the faculty collective bargaining unit agreement. The university will fully cooperate with any investigations conducted by federal officials.”