A Tennessee teenager may not be allowed to attend his high school graduation after administrators found a knife inside his father’s car and slapped the student with a 10-day suspension.

On Thursday, during a random lockdown at Northeast High School in Clarksville, the car that David Duren-Sanner drove to school was chosen to be searched, according to News Channel 5. Duren-Sanner, a senior, said he gave permission for officials to look inside the car because he had nothing to hide.

But administrators found a knife belonging to his father -- who is a commercial fisherman -- wedged between the seats. Duren-Sanner said he did not know about the knife.

Duren-Sanner was suspended for 10 days and reprimanded to attend 90 days at an alternative school. He plans to appeal the suspension at a hearing Wednesday with the school board.

If the suspension is upheld, Duren-Sanner may not be able to walk at graduation, attend prom or his JROTC ball, and he may not be able to graduate at all, his family told News Channel 5.

Duren-Sanner is also facing weapons charges from the Montgomery County Sheriff’s Department.

More than 900 people have signed an online petition in support of Duren-Sanner, calling for the school to drop the punishments against him. The school did not respond to requests for comment from News Channel 5.

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