The unidentified youth also posted videos of himself at target practice and photos of him posing with guns, News 12 said.
Mount Pleasant police investigated and found that the boy was not a threat, News 12 said.
School officials told News 12 that it has taken steps to protect students, but some parents said they are still concerned enough to keep their children home Friday.
Police could not confirm Wednesday night that the student had been suspended and school officials could not be reached for comment.
To read the News 12 story, click here.
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