On Air Desgins

The ruling means that the boy, now 12, could be sent to a juvenile prison until age 23.

Prosecutors argued he killed his father, Jeff Hall, 32, to stop him separating from the boy's stepmother.

Defence lawyers said the boy, who had grown up in an abusive environment, was too young to know right from wrong when he pulled the trigger in May 2011.

Hall was shot at point-blank range as he slept on a sofa in the family's home.

Prosecutors said Hall's white supremacist beliefs had nothing to do with the killing.

At issue in the case in Riverside County, 60 miles (96km) east of Los Angeles, was whether the boy acted with premeditation.

In her ruling, Judge Jean Leonard said she had considered the boy's age, his understanding of the crime and the physical abuse he had suffered at the hands of his father.

"The minor knew what he did was wrong," the judge ruled. "He put the barrel of a handgun to his father's head and pulled the trigger.

"There was planning and understanding in the commission of this crime."

Jeff Hall was the regional director for a neo-Nazi group called the National Socialist Movement, and had led Nazi-style rallies in his hometown of Riverside, according to the Press-Enterprise newspaper.

The boy's younger sister supported the prosecution's case by saying that her brother had planned the shooting days in advance.

The boy had also told police he did not expect to get in trouble because he had seen an episode of the television show Criminal Minds in which a child killed an abusive father and was not arrested.

Prosecutors noted that the boy had a history of violence dating back to nursery school, when he stabbed a teacher with a pencil.

He will be sentenced next month, and his defence lawyer said he hoped his client would be placed in a private facility that offers therapy and schooling, rather than a juvenile detention centre.