Lincoln Brown, a 48-year-old Chicago Public Schools teacher, has filed a federal lawsuit against the district after being suspended without pay for five days for using the “n-word” as a part of a lesson highlighting the “perils of racism,” the Chicago Sun-Times reports. The incident occurred last October when Brown said he used the n-word after two of his students were passing notes with rap lyrics that included it, according to the Sun-Times. The lawsuit alleges Brown used the word during a “teachable moment” in the context of the book Huckleberry Finn in order to show how such language can hurt. But as the words left Brown’s lips, the school’s principal walked in to the Murray Language Academy classroom. Murray Principal George Mason charged Brown with “using verbally abusive language to or in front of students” as well as “cruel, immoral, negligent, or criminal conduct or communication to a student, that causes psychological or physical harm.”