A jury has retired to consider its verdict in the "sad case" of a Wellington journalist who died after he was beaten and left unconscious last year.

Manuel Robinson, 18, and Nicho Waipuka, 20, have been on trial in the High Court at Wellington for the murder of Radio New Zealand journalist Phillip Cottrell.

Mr Cottrell, who had brittle bones due to a genetic condition, suffered a shattered skull in an attack in central Wellington as he walked home from work early on December 10 last year. He died in hospital the next day.

A jury of seven women and five men have sat through two weeks of evidence from more than 65 Crown witnesses


Summing up the case this morning, Justice Forrest Miller said Mr Cottrell had died violently and had done nothing to provoke the attack.

"He was just walking home from work," he said.

"This is a sad case. We all have great sympathy for Mr Cottrell and his family."

Justice Miller said the accused had "behaved despicably" and the jury had not heard much about them that was positive.

But the jury could not allow that to influence their decision, and they had to consider the case on the evidence.

Justice Miller said friends and family of the accused had been reluctant to give evidence, which the jury could take into account, but it did not reflect on the accused.

The Crown case was that Mr Cottrell was overwhelmed in a brief but violent attack.

One of the scenarios the jury must consider was that both men had given the fatal blow.

The jury could also find that one or the other man had delivered the fatal blow, with the other man acting as a party by encouraging the crime.

Justice Miller said the Crown had to prove the men acted with murderous intent in order to find them guilty of murder.

If they could not prove murderous intent, the men could still be found guilty of manslaughter.

Waipuka's lawyer Paul Paino had said his client admitted punching Mr Cottrell once, but if anything he was guilty of manslaughter, not murder.

Robinson's lawyer Mike Antunovic had argued his client was across the other side of the road when the attack happened, and he had not delivered the fatal blow or encouraged the attack.

The jury retired shortly after 10.10am after Justice Miller spent just over an hour summing up.