A meth-crazed madman decapitated his mother — then answered the door to cops while naked, before tearing up and eating a confession that he “killed” her.

Trevor John Huber, 43, was sentenced Tuesday to spend the rest of his life in prison without the possibility of parole for the barbaric murder of his 63-year-old mother, Charlotte Wilson, at the home in Cardwell, a small rural town in Missouri, KAIT reported.

He had called 911 in the early hours of Dec. 21, 2018 to request an officer to come to the house — then answered the door naked and was naked as well as “disoriented and possibly impaired by illegal narcotics,” a probable cause affidavit noted.

When they arrived, he answered the door naked and appeared “disoriented and possibly impaired by illegal narcotics,” according to a probable cause affidavit.

Police found the horrific scene inside, with Wilson’s body without her head — and a bloody knife and hammer used to kill her left on the kitchen table.

Huber was arrested at the scene. During an interview with police, he admitted that he “was concerned he killed his mother” — blaming it on a paranoid conspiracy that she was trying to poison him.

He also confessed to using methamphetamines in the days before the killing.

Huber eventually wrote “I killed my mother” on a piece of paper, then tore it up and swallowed it.

He was convicted of first-degree murder after a two-day trial, KAIT reported.

“I want to thank the Dunklin County Sheriff’s Office and the Missouri State Highway Patrol for their professional and diligent work in investigating and solving this homicide and in all the cases they handle,” Dunklin County Prosecuting Attorney Nicholas Jain said in a statement.