A 17-year-old was charged with trespassing at a Selden high school Monday, authorities said Tuesday.

He was spotted at Newfield High School in Selden about 9:50 a.m. Monday but is not a student there, Suffolk police said. He was charged with third-degree criminal trespass, police said.

But the teenager, who was not identified, is a student in the school district, according to a statement from Roberta Gerold, superintendent of the Middle Country school district.

Following district policy, officials contacted police, Gerold said, and the student was escorted off campus.

“As always, the Middle Country Central School District prioritizes the safety of our students, faculty and staff,” the superintendent wrote. “The District reminds all Middle Country Central School District students that they need special permission to attend a school building within the District if they were not already registered at the beginning of the school year.”

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