California teacher berates student for wearing 'thin blue line' mask: Reports

A California teacher berated a middle school student for wearing a pro-police face mask, denouncing the "thin blue line" mask for being a version of the Confederate flag, according to video being circulated on media. 

Student Lucas Lillar wore the mask to support law enforcement officers, and was castigated by a substitute teacher in math class last week at Lyman Gilmore Middle School in Grass Valley, according to reports.

“That’s not the American flag, that’s the new Confederacy flag,” the teacher appears to say in the video that was recorded by other students.

The teacher argued with the 13-year-old for some 20 minutes, according to the student. 

“I was confused because I didn’t know what he was talking about at first," Lillar told "Fox & Friends., adding: "And then he kept saying that is un-American and how if police don’t like you, they’ll shoot you."

Lillar has law enforcement in his family, according to reports.

The Nevada County, California Superintendent of Schools Scott W. Lay said the incident is under investigation.