PALMER — A popular Wasilla fourth-grade teacher faces felony charges of sexually abusing minors after three students said he touched them inappropriately over a period of years.

Officials from the Matanuska-Susitna Borough School District on Thursday began the process of making sure there aren't more victims.

They also moved to terminate Lukis Nighswonger, the 36-year-old Wasilla man known as "Mr. Nigh" who's taught at Iditarod Elementary School since 2005.

Nighswonger was arrested Wednesday night on charges relating to several incidents of inappropriate touching involving three students that began in 2008, court documents show.

No charges were filed against Nighswonger until now.

The arrest stunned the school community, several parents of Iditarod students said Thursday. Nighswonger, a BP Teacher of Excellence in 2015, was described as a sought-after teacher who'd earned a reputation for high academic standards.

Nighswonger is being held on $50,000 cash bail set during an arraignment hearing at the Palmer courthouse on Thursday afternoon.

The teacher on Monday admitted to School District administrators at their Palmer headquarters that he put his hands down a female student's pants several years earlier, charging documents said. He was taken to the Wasilla Police Department for questioning.

Nighswonger was asked to come in after the district on Friday received a report that prompted administrators to put him on administrative leave effective Monday, according to district superintendent Monica Goyette. She declined to comment on the specifics of the report.

The district began the termination process against Nighswonger after he was arrested, Goyette said.

Nighswonger was taken to the police station after it became clear the report involved Iditarod, a school of about 350 students located in a new building just inside city limits.

At the station, Nighswonger told investigators he was a pedophile, according to a sworn affidavit filed with charging documents Thursday morning.

The incident that started the ongoing investigation involved a former fourth-grade student Nighswonger was helping at her desk, the affidavit says. He said he started rubbing the girl's back, then reached into her pants.

Nighswonger eventually acknowledged there were probably other victims police didn't know about yet, according to the affidavit filed by Wasilla police investigator Dan Bennett.

He left the station that day with his wife and his father.

The girl, interviewed Wednesday, described two incidents that occurred in 2014 in which the teacher put his hand under her shirt and also touched her pelvic area, the affidavit states. She said Nighswonger would put his hand on her buttocks.

But the charging document also revealed other victims had come forward earlier without charges filed against the teacher.

A 9-year-old boy interviewed by a Wasilla investigator in 2012 said Nighswonger touched his penis in 2008, according to the affidavit. The boy said he'd also seen the teacher put his hands up a girl's blouse and down another boy's pants. He described "a lot of pinching and tickling with the students."

No charges were filed in that case due to "insufficient evidence" though police secretly recorded two phone conversations between the boy's father and Nighswonger, the document says. During the second call, confronted about the specific allegation by the parent, he said "this is huge" and that he felt panicked because the accusation could end his career.

But Nighswonger never admitted he did anything wrong, Wasilla police spokeswoman Amanda Graham said Thursday. And no other students came forward.

A 14-year-old girl in January filed a "report of harm" with the state Office of Children's Services saying Nighswonger — a family friend — touched her vagina through her clothes "around 2013" when she came to visit his classroom, according to the affidavit.

Nighswonger, in a follow-up interview with police Wednesday, said he didn't think he touched the girl inappropriately, the document says. But he said he presumed he touched the boy because he had "a guilty feeling."

"He added he has been attracted to kids for as long as he can remember," Bennett wrote.

Police arrested Nighswonger and charged him with three counts of second-degree sexual abuse of a minor, a felony. He was taken to Mat-Su Pretrial Facility.

Arraigned by video Thursday afternoon, he complained about not being able to secure jail phone rights to start the process of getting a lawyer.

Judge John Wolfe set his bail, which also includes a $50,000 appearance bond, at the level requested by a prosecutor, who called Nighswonger not only a flight risk but a risk to the community.

Wolfe also barred him from contact with any minors, including his own two children, except by phone.

Nighswonger told the judge he hoped for lower bail, given his cooperation with authorities so far.

"But it doesn't sound like I'd be able to make bail in any case, so I'm not too worried about it," he said.

Vincent Clark's son is in Nighswonger's class this year. His daughter had him two years ago. Clark took off work to attend Thursday's arraignment.

He came away disappointed, he said. "It's pretty sad."

Clark doesn't think either of his children were touched inappropriately, he said before the arraignment. But his daughter did say something about how Nighswonger sometimes touched her hair. Students always ran up to give him hugs.

Clark said he and the boy's mother switched their son into his class this year. Now he wonders if they put him in harm's way.

"He always told the kids … he was more interested in them getting a good education than being on their best behavior," Clark said.

Nighswonger was a "very high-achieving educator, very popular, well-respected," Goyette acknowledged.

"I think that oftentimes that leads to trustworthiness, and that trustworthiness leads to access with children," she said. "That isn't an uncommon profile, unfortunately, for somebody that might do that in this setting."

At Iditarod Thursday, a substitute certified teacher took Nighswonger's class as the principal met with all fourth-grade families, both one-on-one and in two planned sessions in the morning and afternoon.

School officials are going over fourth-grade rosters, not just this year but for classes that have since moved up to Wasilla middle and high schools.

School district leadership, school psychologists and counselors will be at Iditarod this week and into next if needed to help students and staff, Goyette said.

"This is going to be hard on the whole school community," she said.

Police have established a specific reporting line at 907-352-5418.