A California boy charged with murdering his neo-Nazi father when he was 10 said in a videotaped police interview played in court on Wednesday (overnight NZT) that he was physically abused at home and committed the shooting because he "wanted everything to stop".

The emotionally charged video of statements Joseph Hall made to a police detective hours after the shooting was shown on the second day of the boy’s juvenile court trial stemming from the May 2011 killing of his father, 32-year-old Jeffrey Hall.

Prosecutors and defence lawyers agree that the boy, who is now 12, killed his father by shooting him in the head at near point-blank range as the elder Hall slept on the couch in the family's home.

Since the boy is charged as a juvenile, the purpose of the trial is not to determine his guilt or innocence, but whether certain allegations about his motives are true and whether he can thus be held criminally responsible for the fatal shooting.

The outcome hinges on the boy's understanding of right and wrong at the time.

If the prosecution prevails, the boy could be sentenced to a juvenile detention facility until the age of 23.

Defence lawyers have said the boy was conditioned by his father’s violent, racist behaviour and killed Jeffrey Hall to put a halt to the physical abuse inflicted on him by his father.

Prosecutors have said the boy, who lived in a house with four siblings, committed the slaying because his father was threatening at the time to divorce his stepmother, Krista McCary.

Prosecutors said he was close to McCary and considered her his true mother.

Joseph’s responses to questions put to him in the recorded interview by police detective Roberta Hopewell appeared to cast some doubt about the boy’s grasp of the consequences of his actions.

Asked what he thought would happen after he shot his father, the boy replied, "I thought he’d be dead".

But later in the interview, he said he had hoped that after his father was shot, "they could fix him and we could be friends again". He also said he was inspired in part by an episode of a police television drama in which an abusive father was shot to death as he slept by his young son.

"And what happened to the kid?" the detective asked.

"Nothing, he just told the truth," Joseph answered.

’I SHOT MY DAD’

Joseph also confided that he "didn't want (the shooting) to look like I did it on purpose" and admitted hiding the gun under his bed afterward.

Asked by Hopewell to give an example of something that's "wrong", he answered: "I shot my dad."

The case in Riverside County, east of Los Angeles, has drawn attention for Jeffrey Hall's neo-Nazi associations and the rarity of a parent being slain by a child as young as Joseph.

Kathleen Heide, a criminologist who specializes in juvenile offenders, has said 8000 murder victims over the past 32 years were slain by their offspring, but only 16 of those were committed by defendants age 10 or younger.

In his videotaped interview following the shooting, Joseph told police his father was physically abusive, especially toward him, saying: "My dad was roughest on me" and that "he kicked and beat me".

He also said he "didn't want my mom to leave", referring to his stepmother.

Asked about what he was thinking before shooting his father, Joseph said he thought: "I should end things. I wanted everything to stop."

Also in court, the boy's 11-year-old sister, Shirley Hall, took the witness stand, testifying that Joseph had told her beforehand that he intended to shoot her father.

Looking nervous, she broke down in tears near the end of her questioning.

- Reuters