AUGUSTA — A former teacher at Monmouth Middle School pleaded guilty Wednesday to possession of sexually explicit materials and theft of a school laptop that contained photographs of nude children.

Christopher Brown, 55, of Monmouth was sentenced in Kennebec County Superior Court to 30 days on the theft charge. A sentencing hearing on the other charge — a felony — was postponed for 12 months.

“The point is to get you the counseling that you apparently need,” Justice Nancy Mills told Brown.

Maine State Police Sgt. Glenn Lang said earlier that Brown admitted to using the laptop computer to put images of the heads of local students on other bodies. Investigators said it did not appear that any of the children from the middle school were in the nude photographs.

The theft occurred Nov. 2, 2010, and the possession of sexually explicit materials occurred June 8, 2011, both in Monmouth, according to court records.

An additional theft charge and a charge of making a false public report — falsely reporting that the laptop had been stolen — were dismissed in exchange for the guilty pleas.

Under a sentencing arrangement approved by Mills, if Brown complies with certain conditions for the next 12 months, he can withdraw his guilty plea to the felony charge and plead guilty to a misdemeanor charge of possession of sexually explicit materials.

Those conditions say he must prove he is attending sex-offender counseling, refrain from possession of sexually explicit materials and refrain from contact with children younger than 16, except for incidental contact, and have only supervised contact with his grandchildren.

If Brown is successful, he will be sentenced on the misdemeanor charge to a fully suspended 364-day jail term and one year of administrative release with the same conditions.

If Brown is unsuccessful, the guilty plea to the felony will remain and he will face a maximum jail term of five years, Mills said.

Assistant District Attorney Paul Rucha told the judge that an employee of Regional School Unit 2, the school district that includes Monmouth, reported finding “disturbing images” of children on the playground and checked laptops of teachers who taught those students.

Brown’s laptop was reported missing, and Brown later led state police to where he had hidden the school computer outside his home, Rucha said. Rucha also said Brown admitted to taking the photos.

Brown was a fifth-grade teacher at Monmouth Middle School for more than a dozen years and was placed on administrative leave after his arrest. He later retired.