A substitute teacher at an alternative school in Auburn was indicted this week on a charge that he had sexual relations with a teenage student last year.

Tyler Gadaire, 31, of Turner, was charged with a single count of gross sexual assault. He is accused of having an ongoing relationship with the student that involved sexual contact in a classroom, secret meetings in a school quiet room and encounters at a Bath hotel.

Gadaire is accused of having sexual relations with the girl who was then 17 and a student at the Androscoggin Learning and Transition Center, a behavioral alternative school on Poland Road.

Gadaire was a substitute teacher at the center between September and December of 2025. He was ultimately fired from the position after school officials learned he had been having private communications with the girl in violation of school policy, according to documents.

An Auburn police investigation began around the same time. In a police affidavit written by Detective Marshall W. McCamish, officials said the girl ultimately confessed to having numerous sexual encounters with Gadaire and said it was consensual.

Under Maine law, sexual abuse of minors includes when someone at least 21 years old engages in a sexual act with another person who is either 16 or 17 years of age and is a student enrolled in a school where the accused is a teacher or other employee.

Police said the teacher would meet the girl in a quiet room to pass notes with the instructions that all notes were to be destroyed after they were read.

Police also found evidence that Gadaire booked a hotel room in Bath near the girl’s place of employment, according to the affidavit.

While investigating the alleged sexual relationship, Auburn police worked directly with investigators from Bath. In January, Bath police provided Auburn detectives with a “love letter” said to have been written by Gadaire to the teenage girl.

Gadaire was arrested in March. Described as a behavioral health professional and educational technician III, Gadaire was booked at the Androscoggin County Jail and later released.

On Tuesday, he was indicted on the Class C charge of gross sexual assault by the Androscoggin County grand jury, which accepted the police claim that the charge was appropriate because Gadaire had been in a position of authority over the girl.

If convicted, Gadaire could be sentenced to up to five years in prison. His next court appearance is scheduled for December.