A Wisconsin judge described Patterson as "one of the most dangerous men to walk the planet" in delivering the maximum sentence on Friday.

Barron County Circuit Court Judge James Babler said Patterson, 21, was a danger to society due to his fantasies of "taking multiple girls, and killing multiple families" and he could never be released from prison.

Judge Babler sentenced Patterson to two consecutive life sentences in addition to a 40-year sentence for Closs' abduction, describing the former cheese factory worker as "the embodiment of evil".

Patterson, 21, has admitted to committing the October killings and abduction in Barron County, telling investigators Closs "was the girl he was going to take" after he saw her get on a school bus.

"Because of this monster, Jayme won't have her mom and dad at her dance recitals," Mike Closs, Jayme's uncle, said in court.

Following the hearing, Closs' aunt Jennifer Smith said the family was satisfied with the sentence and knew it would give Jayme peace.

"She lives in fear, doesn't have a normal 13-year-old life, and that's all from what you did," Smith told Patterson in court. "I won't let you destroy our family no more. We can be happy."

Police say Patterson carefully planned the crime, shooting Closs' father through the front door with a shotgun. He broke down the bathroom door where Closs and her mother were hiding, bound the girl with duct tape, then shot her mother.

He put Closs in the trunk of his car and drove to his cabin in Gordon, about 97 km north of Barron. She escaped on January 10 when Patterson left the cabin. A dog walker found her, neighbours called 911 and police arrested Patterson.

Australian Associated Press