A Christchurch man killed his former partner with a military-style sleeper hold because he was jealous and wanted revenge, a court has been told.
Nikki Roper is accused of murdering 21-year-old Alexsis Tovizi in December 2010.
The 24-year-old is also charged with unlawfully taking Ms Tovizi's car, stealing her laptop and five counts of dishonestly using her eftpos card.
He denied all charges at the start of his trial at the High Court in Christchurch on Monday.
In his opening statement, Crown prosecutor Marcus Zintl said Nikki Roper strangled Alexsis Tovizi in early December 2010, just days after being released from prison for trying to choke her two months earlier.
Mr Zintl told the court Mr Roper's actions were fuelled by jealousy towards Ms Tovizi's new boyfriend.
"The Crown case is that Mr Roper, fuelled by jealousy and revenge, over Ms Tovizi's relationship ... strangled her and killed her or strangled her and then drowned her."
The court was told Nikki Roper told an inmate that he would kill Ms Tovizi after he got out of jail on 1 December 2010 and that he would be back for a longer sentence.
Mr Zintl said Mr Roper told an associate that he had fed Ms Tovizi sleeping pills before choking her, and had also told people that he had killed her for cheating.
However, he said jurors would also hear evidence suggesting that the accused assisted Ms Tovizi's suicide.
Mother gives evidence
Ms Tovizi's mother told the court on Monday her daughter was not suicidal.
Cheryl Tovizi said her daughter had had depressed episodes in the past but at the time she died she was enjoying life and had so much to look forward to with her new partner.
She said she urged her daughter to use the protection order that was in place if Mr Roper came round to her house, but Alexsis told her she could handle the situation.
The defence is yet to make its opening statement. The trial is expected to last a week and a half.