AUGUSTA — A man found not criminally responsible for sexually assaulting and killing his mother-in-law in front of his 6-year-old daughter in 2014 pleaded guilty Monday to possessing child pornography while in the custody of Riverview Psychiatric Center and was sentenced to 18 months in prison.

Paul Orchard, 43, pleaded guilty to one count of possession of sexually explicit material of a minor under 12 years old via video feed from Riverview, at the Capital Judicial Center.

Maine Department of Health and Human Services staff found at least one video of child pornography on a tablet they had taken from Orchard, after staff expressed concerns about things they’d seen on his electronic devices and requested a police search. The material, according to prosecutor Michael Madigan, an assistant district attorney, included sexually explicit video involving a juvenile under the age of 12.

Orchard, who is in the custody of DHHS, was sentenced to 18 months in prison. Orchard agreed to plead guilty to a single, Class C felony charge of possession of sexually explicit material of a minor under 12, while a second, similar charge was dismissed as part of a plea deal.

Orchard was found not criminally responsible by reason of insanity for the 2014 sexual assault and killing of his mother-in-law, Paula Nuttall, 57, in front of his then-6-year-old daughter in the family’s home in Peru. Orchard told police he was on a vapor high from refinishing floors, and was naked and covered in polyurethane when authorities arrived at the home the family shared. He has said he doesn’t remember anything about the incident.

An autopsy determined that Nuttall died of cardiac arrest during strangulation.

Orchard was ordered into DHHS custody following the finding he was not criminally responsible, and he must petition the court to seek changes in his privileges. In 2022, when he was living in a group home in Augusta, Orchard was granted up to eight hours of unsupervised time in the community following a court hearing.

It was not immediately clear where or how Orchard accessed sexually explicit material on his tablet.

Orchard will be required to register on Maine’s sex offender registry for the rest of his life.

Orchard’s mental competency to proceed in the child porn case was evaluated and his lawyer, Jennifer Cohen, said in court she had no concerns about his competency.

Capital Police and the Maine State Police computer crimes unit investigated the case.