A Missouri high school student who recorded a teacher using a racial slur in class was suspended for three days.

An unnamed geometry teacher was placed on administrative leave after a video shot by student Mary Walton at Glendale High School in Springfield emerged.

In the video, which went viral, the teacher can be heard asking why Black people can use the n-word but it is offensive when other people do so, reported The Riverfront Times.

In the video, the teacher can be heard using the word two times, with one student warning the teacher about using it and another gasping in shock.

Mary Walton says that she only shared the video with her mother and a friend but that it went viral from there even though she did not post it on social media.

But now her lawyer says that the teenager has been suspended for three days for violating the school district’s electronic device policy.

“Mary saw a teacher do something wrong, and she documented it,” attorney Natalie Hull told The Riverfront Times.

“Language can be harmful, and Mary captured proof of her teacher, a person who is supposed to protect children, harming them through his use of a racial slur.

“If he had been hitting a student — or worse — would the school have reacted the same? Frankly, this school is exercising a chilling effect on all of the students by sending the message that they will get in trouble if they capture evidence of their teachers doing something wrong.”

The Independent has reached out to the school district for comment.