A student was arrested Tuesday for allegedly posting the photo and threatening remarks.
Howell Township police shared the post in which a rifle can be seen between the person's legs with the caption "Don't pu Tomorrow."
The threat was not credible, Howell Police Chief Andrew Kudrick and Howell High School principal Jeremy Braverman said.
Kudrick said that within an hour a student was in police custody, The gun in the photo turned out to be an Airsoft.
"Although not a real firearm it certainly is identical to an actual rifle," Kudrick said, "This was a poor decision by this juvenile."
The student's name was not released.
Braverman said, "The student that posted these remarks will not be in school for the immediate future."
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