A California judge found Monday that a boy was responsible for the second-degree murder of his white supremacist father when the defendant was just 10.

Prosecutors had argued at trial that the boy, now 12, knew what he was doing when he shot 32-year-old Jeff Hall — a regional leader of the National Socialist Movement — and the slaying was premeditated.

Defense attorney Matthew Hardy countered that his client grew up in an abusive and violent environment and learned it was acceptable to kill people who were a threat. Hardy contended the boy thought if he shot his dad, the violence would end.

The boy, who is not being identified by The Associated Press because of his age, did not testify at the trial.

Riverside Superior Court Judge Jean Leonard heard the case without a jury.

Leonard said in the ruling that the killing was planned by the boy but noted the amount of abuse he suffered at the hands of his father had an effect on his life.

“This was not a complex killing,” Leonard said. “He thought about the idea and shot his father.”

The boy showed no emotion when the judge gave her ruling. A sentencing hearing was set for Feb. 15. He could be jailed until he is 23.

Prosecutors argued that the child killed his father to keep him from splitting up with his stepmother, who initially said she had killed Hall but then quickly retracted her statement. She was not charged in the case.

The boy’s younger sister bolstered the prosecution’s case by saying her elder sibling plotted the shooting days in advance.

Hall was shot at point-blank range with a .357 Magnum while he slept on a sofa in the family home.

The boy said in a videotaped interview with police that he didn’t think he’d get in trouble because he saw an episode of “Criminal Minds” in which a child killed an abusive father and wasn’t arrested.

Prosecutors maintained Hall’s white supremacist beliefs had nothing to do with the crime. They noted the boy had a history of violence that dated back to kindergarten when he stabbed a teacher with a pencil.

Hardy said he hopes the boy, if convicted, would not be sent to a juvenile lockup but rather be placed in a private facility that offers therapy, medical treatment and schooling.

(AP)