Tajinder Tung, 48, of Stewartsville, "stalked a student and committed acts that constituted a course of alarming conduct, both inside and outside of the school" while he was teaching at the high school between 2017 and May 2019, Morris County Prosecutor Fredric M. Knapp and Acting Chief of Investigations Chris Kimker said in a joint release.
Tung originally was arrested and charged on a complaint in August.
The case was then presented to the grand jury, which returned the indictment against him.
Authorities asked that anyone with additional information involving Tung contact Detective Matthew Magnone of Knapp's office at (973) 285-6200, or Mount Olive Police Detective Lt. Luis Sanchez at (973) 691-0850.
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