The Mount Vernon school board fired John Freshwater in January, following a state hearing officer's recommendation.
The board filed notice with U.S. District Court in Columbus on Tuesday to move the case to the federal court system because Freshwater's appeal involves an allegation his constitutional right to express a religious opinion was violated.
Freshwater was accused of preaching Christian beliefs in class and of using a scientific device to mark students' arms with a cross. The hearing officer said there was a plausible explanation for that but didn't explain further.
Freshwater did not immediately return a message seeking comment.
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