It was an otherwise unremarkable Wednesday at Pembroke Academy when the police showed up at the New Hampshire high school to investigate a report: The dean of students, Rekha Luther, said she had found a bundle of hypodermic needles on campus – and then misplaced them.

It was an odd claim, police later said, and officers never found the missing needles, determining along the way that there had never been any missing needles at all, said Dwayne Gilman, chief of Pembroke police.

But in searching, Gilman said, police did make a discovery: Heroin in Luther’s office and three kinds of anabolic steroids in her car.

The public high school’s 850 students were in class when police handcuffed Luther – the administrator responsible for discipline – and led her out a back door and into a police car.

She was charged with four felony counts of possessing a controlled substance, and released the same day on $10,000 bail, according to court documents. She later submitted a letter of resignation from Pembroke Academy, a public high school in a middle-class, suburban community outside Concord.

“Everyone was kind of shocked about the whole issue, because it isn’t someone you would think – well, I shouldn’t stereotype,” Gilman said. “She’s probably one of the last people that anyone thought.”

But not everyone was shocked because, for the most part, parents and students had no idea what had happened.

Luther was arrested at school on Feb. 17. But the allegations did not come to light for another six weeks, when Jeanne LaBarge, the mother of a Pembroke Academy student, noticed Luther’s name in police arrest logs.

LaBarge couldn’t find anyone who knew what had happened or why Luther’s name had been removed from the school’s website. Disturbed, she alerted the local newspaper, which published a story on April 1 about Luther’s arrest.

“It’s amazing to me how they kept this so quiet,” LaBarge told the Concord Monitor. “Heroin’s a big deal right now, and it is a problem. But how we deal with problems – we should be setting an example of how to deal with the problem, not trying to hide it.”

Luther, 36, has pleaded not guilty to each of the charges against her. She did not respond to a request for comment, and nor did Michael Iacopino, the attorney listed in court papers as her representative.

School officials said that they did not announce Luther’s arrest because it is a personnel matter that they are legally bound to treat confidentially.

Superintendent Patty Sherman said she understood why parents were upset that they hadn’t been notified. But she said that she could not disclose anything about a personnel matter unless students’ safety was threatened – and that wasn’t the case, she said in an interview Monday.

“If there is a risk to student safety, that would trump anything,” Sherman said.

In the coming weeks, Pembroke Academy will host a long-planned community forum to discuss the local and statewide results of a youth survey that measures teen drug use and other risky behaviors. Sherman said she hopes the forum will give parents and students a chance not to to publicly confront problems of drug use and abuse. As for Luther? “She will not be discussed,” Sherman said.

New Hampshire, like many states, is grappling with a surge in the use of heroin and prescription narcotic painkillers. More than 400 people in the state died of drug overdoses in 2015, according to New Hampshire Public Radio.

One of those people was Luther’s fiancé, who died in June, according to his obituary in the Newburyport Daily News.

Luther had been a high school social studies teacher in Nashua, N.H., for a decade until last year, according to that district’s superintendent. She left that job when she was hired at Pembroke. “Ms. Luther blew the interview team away,” read the minutes of the Pembroke School Board’s September meeting.

Gilman, the police chief, said he does not believe that Luther was dealing drugs to anyone, and certainly not to students, given the small amounts police found. “I feel pretty confident that it’s personal use,” he said.

Gilman said it’s sad that heroin is in Pembroke’s schools, but he said it’s not surprising. The drug is everywhere, he said, and it has killed all kinds of people.

“We know this heroin problem isn’t going anywhere soon,” he said.

He said he doesn’t know why Luther reported that she had misplaced a seemingly fictitious bunch of needles, setting in motion the search that ended in her arrest. When police handcuffed her, she was not under the influence, and was “very pleasant, very cooperative, understanding of our job,” Gilman said.

But she didn’t offer any explanation.

“People in times like that either talk or don’t talk,” he said. “She chose not to talk.”