Nikki Roper strangled his ex-girlfriend Alexsis Tovizi to death with a sleeper hold just days after being released from prison where he was serving a sentence for choking her, a court heard today.
When he was leaving jail, a fellow inmate told him to take care of his missus and to not come back.
"I'll be back for the big one - I'll kill the b****," Roper replied, according to the Crown on the opening day of his murder trial at the High Court in Christchurch.
Roper, a 24-year-old unemployed man from Sockburn, this morning pleaded not guilty to murdering mother-of-one Ms Tovizi.
Crown prosecutor Marcus Zintl told the jury of eight women and four men that it was a murder "fuelled by jealousy and revenge" after Ms Tovizi had started a relationship with another man.
He said Roper choked his "on again, off again" 21-year-old partner to death with a sleeper hold at her Stanmore Rd home between December 5 and 9, 2010.
He may have then stuck her head in a bucket or pot of water, before putting her to bed, Mr Zintl said.
The following day, Roper allegedly took her laptop, cellphone, bank card, and put her three-year-old son in her Subaru car and drove off.
The Crown says he then tried to sell the laptop to an associate for $150, before dropping the child off at his great-grandparents' house, telling them that Ms Tovizi had "done a runner".
He then made withdrawals and purchases with her bank card, Mr Zintl said.
A post mortem examination on her body, which was found by police on December 9, concluded that she probably died of asphyxiation.
Roper would later tell police, when he was arrested in February 2011, and also associates, that he had helped Ms Tovizi commit suicide, said Mr Zintl.
But he said Roper had talked about using a "military-style sleeper hold" on her.
The Crown alleges that Roper also told a fellow inmate who had just pleaded guilty to a murder that he was "dumb", because Roper had just pleaded not guilty and "I killed my missus".
He had also tried to organise a false alibi for the period of Ms Tovizi's death, the Crown alleges.
Ms Tovizi's family members are due to give evidence at the trial, which is before Justice Forrest Miller and is set down for two weeks.
Justice Miller told the jury today that during the trial they would hear Roper had previous criminal convictions, and that he had spent time behind bars.
Justice Miller said it was unusual for a jury to hear such details because it could hinder a fair trial, but said it was necessary in this case in order for the jurors to make some sense of the relevant evidence.
The judge warned, however, that the information did not mean Roper was of bad character, or that he committed the murder.
- Kurt Bayer of APNZ
