A federal judge threw out a former Tennessee student's free-speech lawsuit against a school dress code that banned Confederate flag clothing.

Nearly a year after a jury failed to reach a verdict in Tommy Defoe's case, U.S. District Judge Tom Varlan ruled against a retrial.

The judge said there was undisputed evidence of racial threats against minorities at Anderson County High School and school officials "reasonably forecasted" that clothing such as Defoe's Confederate flag T-shirt and belt buckle would cause a "material and substantial disruption to the school environment."