Teen denies murder of boyfriend after row

A Whangarei woman standing trial for murder stabbed her boyfriend in the heart after he smashed her phone and they argued over access to a social media site, the High Court at Whangarei has heard.

Shaylene Wharerau, 19, is standing trial before Justice John Faire and a seven-man, five-woman jury charged with the murder of Brandon Panapa-Ripia, 17, who was stabbed in the chest during a domestic dispute on October 30, 2012.

He had surgery, but died three weeks later while shopping in Whangarei on November 20.

Wharerau also faces alternative charges of wounding with intent to cause grievous bodily harm and wounding with reckless disregard.

In her opening address to the jury, Crown Prosecutor Bernadette O'Connor said on October 30, 2012, Wharerau and Mr Ripia were at the home they shared with her grandmother at Ross St, Onerahi when they started arguing because Mr Ripia wanted to use his girlfriend's cellphone to access Facebook.

She refused and they started arguing, including them hitting each other.

Ms O'Connor said Mr Ripia smashed Wharerau's cellphone and she went into the kitchen, grabbed a vegetable knife and swung it at her boyfriend.

The knife went into the left side of Mr Ripia's chest, nicked his left lung, went through the sac that surrounds the heart and into the heart itself.

He was operated on, but on November 20, while he was at the Warehouse in Whangarei, Mr Ripia collapsed after the wound in the heart reopened and the sac surrounding the heart filled with about 1.7 litres of blood, causing his heart to stop working and he died.

Wharerau said in her interview with police on the day of the stabbing it was an accident and that she had picked up the knife to scare Mr Ripia and calm him down. She said in the interview that she had held a knife up to him previously and that had calmed him down.

However, Ms O'Connor said, Wharerau also said when she saw the extent of the damage to her cellphone she got angry.

"The Crown says it was a deliberate act - not an accident," Ms O'Connor said.

She said Wharerau swung the knife at Mr Ripia and was reckless as to whether he was injured or not.

Ms O'Connor said the law provides that if a person dies within one year and one day of the action that caused the death the person that caused the action can be held criminally responsible.

She said medical evidence would show that it was the injuries caused by the stabbing by Wharerau that caused the death.

Defence lawyer Arthur Fairley said Wharerau was consistent from the moment of the stabbing by saying it was an accident.

He said she told this to her relatives who lived next door immediately after the incident, said the same to police in her interview that day and that was even backed up by Mr Ripia, who told the nurse tending him and others that day that it was an accident.

Mr Fairley said there was no murderous intent.

He said the jury must also consider the possibility of self defence on behalf of Wharerau.