A former professor's lawsuit following his firing from the University of Colorado has been stopped in its tracks. The Supreme Court won't hear Ward Churchill's case against the school, Reuters reports. He was fired after an investigation cited problems with his academic work, but the probe was sparked by a controversial essay that likened 9/11 victims to Nazi war criminal Adolf Eichmann. Churchill says he was denied free speech, calling the firing a response to the essay. Colorado courts ultimately backed the university, arguing that its "quasi-judicial action" prevented Churchill from suing.