The Supreme Court declined to hear an appeal Monday by former university professor Ward Churchill, who was fired after making controversial statements about the Sept. 11, 2001, terrorist attacks.

Churchill, a former tenured ethnic studies professor at the University of Colorado Boulder, lost his job in 2007 after an investigation uncovered flaws and deficiencies in his academic work.

The university prompted the investigation after Churchill wrote an online essay about the terror attacks on the World Trade Center and the Pentagon. Churchill compared 9/11 victims to Adolf Eichmann, a notorious Nazi convicted of war crimes and eventually executed in 1962.

Churchill claimed he was fired in retaliation for his comments and sued the school, saying his First Amendment rights were violated.

His comments and case caused public outrage.

According to a Reuters report, state courts ruled in favor of University of Colorado, saying in part that the investigation and subsequent determinations made by the school were a “quasi-judicial action” that was the same as a judicial process, meaning that Churchill could not sue.

Click for more from Reuters.