The threats, targeting Myles McManus Middle School, appeared recently on Snapchat, including on Friday.
"Each and every day parents trust us to protect the most valuable people in their lives, and we do not take that responsibility lightly," said Hart. "Any threat to our students, faculty, or staff will be thoroughly investigated and prosecuted to the fullest extent."
Out of "an abundance of caution," there would be a heightened police presence at the school Monday, Hart also said.
The incident remains under investigation by the Linden Police Juvenile Aid Bureau, and anyone with information is urged to contact Det. Steve Zevlikaris at (908) 474-8520.
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