A 12-year-old boy has been jointly charged over the death of West Auckland dairy owner Arun Kumar.
The boy appeared in the Youth Court today where police added a charge of manslaughter to his current charge of assault with intent to rob.
His alleged 13-year-old accomplice appeared in the High Court earlier today charged with murder.
Both boys' names are suppressed.
The pair were arrested following the fatal stabbing of Arun Kumar, 57, in his Henderson dairy earlier this month.
Police presented a new charge to Family Court Judge Tony Fitzgerald who said the case would now be transferred to the High Court.
The boys would now face a joint trial, he said.
Earlier, in the High Court, lawyers for the 13-year-old asked that his fitness to plead be assessed.
Defence lawyer Maria Pecotic asked Justice Graeme Lang that she not enter a plea yet to allow for time for assessments to be made of the boy.
"I'm not satisfied he will be able to understand the seriousness of the charges," Pecotic said.
Justice Graeme Lang said he wanted to set a trial date to ensure it was this year, given the accused's age.
He set a three-week trial for 24 November.
The boy, with his hair neatly parted, stood quietly in the dock throughout the hearing.
His family turned up after his matter had been called and were heard saying "love you bro, stay strong", as he was led into the cells.
Police allege the 13-year-old boy stabbed Kumar in the neck on June 10 while he was working with his wife at the Railside Dairy.
She immediately raised the alarm, but Kumar died shortly after emergency services arrived.
The 13-year-old boy was remanded to a further call-over on August 6.
The 12-year-old was remanded in Child Youth and Family custody.