RIVERSIDE, Calif.—A boy who was 10 when he was charged with fatally shooting his neo-Nazi father is having his trial interrupted for two months because of a conflict over a witness.

Riverside County district attorney spokesman John Hall said Wednesday that the judge halted proceedings until Jan. 7 to allow prosecutors to find a new psychological expert. The judge last week barred the prosecution witness because he also conducted a court-ordered review of the child's mental competence.

The murder trial for the boy, now 12, had been expected to end this week. The AP is not identifying the child.

Prosecutors allege he shot his father, 32-year-old Jeff Hall, as he slept.

Hall was a regional leader in the National Socialist Movement.

The boy has pleaded not guilty by reason of insanity.