He said that, while her family, friends and police frantically searched for Ms Moka, who ran off from the marae followed by her partner on the night of June 8, Korewha took a number of steps to conceal not only her death but also her body.
Mr Smith said Korewha told his employer he went looking for her and, upon finding her, he "lost it".
Although Ms Moka's body was at an advanced stage of decomposition, forensic scientists discovered she had a fractured skull and nose, broken ribs and bruising.
"The nature, number, extent and power of the blows he inflicted and his behaviour and after shows that he murdered Barbara Moka," Mr Smith said.
Korewha sent messages and notices to family and friends inquiring whether anyone had seen her, and even nominated names of people who police should follow up on, he said.
Mr Smith highlighted an incident in January last year when Korewha gave Ms Moka, who had been drinking, two black eyes after becoming angry at the state she was in.
In another incident, she ran off to a school for protection after he chased her.
Her mother Isobel Moka and sister Ladyjane Moka said in evidence they had travelled from Auckland to Omapere to see Ms Moka after she told them about the black eyes.
She was taken to Auckland but returned to Omapere the next day with Korewha, who came to pick her up.
Isobel Moka said her daughter also had bruises on her arms and face from a hiding Korewha gave her because she set up an alcohol tab at a hotel, which he didn't like.
When questioned, she said Korewha told her Ms Moka got the black eye because she was drunk. "I said that's no excuse," she told the court.
Ms Moka's brother Heremaia told the jury he had received a text from Korewha about 10pm on June 9 last year, who asked him to get her to text him. The trial continues before Justice Brendan Brown.
