RUTHERFORD COUNTY, Tenn. (WKRN) A longtime Rutherford County teacher is suing her school district, claiming she was fired for what she shared online.

The federal lawsuit alleges her termination violated her First Amendment.

Susannah O’Brien, a veteran educator in Rutherford County, was dismissed earlier this month after sharing two Facebook posts about conservative commentator and activist Charlie Kirk, who was shot and killed in September.

One post criticized the decision to lower flags in Kirk’s honor. Another, shared from the political page Occupy Democrats, said Kirk “spent his entire life disparaging immigrants, disrespecting women and blaming Black folks only to get shot in one of the whitest places on Earth.”

O’Brien’s attorney, Mark Downton, said O’Brien was punished for expressing a personal viewpoint on her own time.

“It’s a clear violation of her free-speech rights for the government which is what the school board is to punish her for speaking on issues that matter to all of us,” Downton said.

Court filings said O’Brien posted from her personal account “on her own time and her own devices,” and that her page was set to “friends only.” The complaint also notes she never mentioned her employer or identified herself as a teacher.

“This was on her private time, on her Facebook page,” Downton added. “It wasn’t part of her job or connected to the schools. It was just a meme; it wasn’t some diatribe.”

Within a week, O’Brien was placed on unpaid leave. Days later, she was fired for what the district called “unprofessional conduct” that was “not in alignment with the expectations as an educator of Rutherford County Schools.”

Filed Tuesday in the U.S. District Court in Nashville, the 15-page lawsuit accuses Director of Schools James Sullivan and the Rutherford County Board of Education of violating O’Brien’s constitutional rights. The lawsuit seeks reinstatement, pay and damages.

Legal experts say the case will likely hinge on whether O’Brien’s posts caused any disruption at school a key standard in workplace speech cases.

Gregory Magarian, a professor at Washington University School of Law, said the district’s reasoning could set a dangerous precedent if upheld.

“You might be able to say a teacher stood up in class and called Charlie Kirk a terrible person, and that would disrupt the school environment,” Magarian said. “But the government can’t make that argument when a teacher is posting from their own home on their own time.”

He added that allowing districts to fire employees for unpopular opinions expressed privately would erode the very rights public servants are supposed to retain.

“If the school district can win this case, then it’s open season,” Magarian said. “Even if a teacher quietly says at a social gathering, ‘I really disagree with Charlie Kirk,’ and someone posts that online, the district could claim it interferes with the school. That completely guts a teacher’s First Amendment rights.”

O’Brien’s legal team has also filed a temporary restraining order asking a federal judge to reinstate her immediately. A hearing on that motion is set for Friday at 1 p.m. in federal court. If granted, the order would remain in place until a later preliminary injunction hearing is held.

Downton said his client’s goal isn’t just to get her job back.

Rutherford County Schools sent affiliate WKRN a statement Thursday morning, which read: “We did receive a legal notice yesterday. We don’t comment on pending litigation but our legal representatives plan to respond through the judicial process.”