Christopher Tavon Mitchell, 17, made the threat to his teacher after he showed up an hour late to class.
Mitchell was arrested by Cumberland County sheriff's deputies.
He is being held at the Cumberland County Detention Center under a $10,000 secured bond.
This investigation is ongoing.
The sheriff's office reminds parents to be involved with your children and speak with them about the importance of immediately reporting any threats they hear or see. If a child isn't comfortable talking to a teacher, they can anonymously call the Speak Up hot line at (866) SPEAK-UP or (866) 779-8587.