From the FIRE letter:

We are concerned that UCLA may have departed from its commitment to academic freedom and its obligations under the First Amendment by investigating university lecturer Lt. Col. W. Ajax Peris for vocalizing a racial slur in reading aloud from Martin Luther King, Jr.’s “Letter from a Birmingham Jail.” …

Peris’ reading of Martin Luther King, Jr.’s “Letter from a Birmingham Jail” is unequivocally protected by fundamental principles of academic freedom and the First Amendment. If UCLA does not intend to initiate a formal investigation, it should publicly clarify as much in order to mitigate the possibility of a chilling effect. If it has mounted such an investigation, it must abandon it….

Courts have long recognized that the First Amendment’s protection of freedom of speech is closely intertwined with academic freedom. Universities “occupy a special niche in our constitutional tradition,” and “academic freedom” is an area “in which government should be extremely reticent to tread.” As the Supreme Court has explained:

“Our Nation is deeply committed to safeguarding academic freedom, which is of transcendent value to all of us and not merely to the teachers concerned. That freedom is therefore a special concern to the First Amendment, which does not tolerate laws that cast a pall of orthodoxy over the classroom.”

To be sure, in Garcetti v. Ceballos, the Supreme Court upheld the power of non-academic government employers to regulate their employees’ speech that is pursuant to their employment duties. The Garcetti court, however, reserved the question of “whether the analysis we conduct today would apply in the same manner to a case involving speech related to scholarship or teaching.” As Justice Souter’s opinion stressed, that ruling should not be read to “imperil First Amendment protection of academic freedom in public colleges and universities,” which freedom encompasses “the teaching of a public university professor.” Accordingly, the United States Court of Appeals for the Ninth Circuit—the decisions of which are binding on the University of California—has expressly recognized that expression “related to scholarship or teaching” falls outside of Garcetti. {Demers v. Austin, 746 F.3d 402, 406 (9th Cir. 2014). Other courts have reached similar conclusions. See, e.g., Adams v. Trs. of the Univ. of N.C.-Wilmington, 640 F.3d 550, 562 (4th Cir. 2011) (Garcetti does not apply in the “academic context of a public university”) ….}

The whole letter is much worth reading. (This is the incident I wrote about here.)