Alhough he wasn't deemed a threat, the video led to charges of creating a false public alarm against Joseph Rafanello, 18.
Rafanello, who authorities said won't be returning to the school, remained held at the Essex County Correctional Facility in Newark on Saturday pending a detention hearing.
"At this point our investigation has not uncovered any further active security threats to any of our public schools and we will continue to work with the school district to ensure the safety of our schools," Nutley police said in a statement Friday night.
"This is just a proactive measure and not related to any further threats," it said. "We will be increasing patrols around all our schools when school begins on Monday."
Authorities said they identified others in the video and received their cooperation in the investigation, which began after the Instagram post on Feb. 15, a day after the Parkland massacre in Florida.
Nutley schools were closed on Friday, Feb. 16 as a precaution.
The video includes Foster the People's "Pumped Up Kicks" as part of the soundtrack -- including the lyrics: "You'd better run, better run, outrun my gun. All the other kids with the pumped up kicks. You'd better run, better run, faster than my bullet."
"I want to commend those individuals who spoke up last week and alerted administration to a possible threat," Nutley Schools Supt. Julie Glazer said in a statement. "This was our process working. People saw something and said something, allowing for the swift, collaborative actions, which kept our schools and town secure.
"The police have been in each of our schools this week and have assured us that our buildings are secure and there is no reason to believe there is any further threat or cause for alarm."
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