Defense lawyers said Millane died accidentally as the result of a consensual sex act that went wrong. They said the man restricted Millane's breathing by applying pressure to neck, according to news site RNZ.
Millane's body was found in a forested area in the Waitakere Ranges near Auckland a week after she disappeared last December on the eve of her 22nd birthday. She had been traveling through New Zealand as part of a planned yearlong trip abroad after graduating from university.
The 27-year-old man charged with murdering Millane has pleaded not guilty. His name is being kept secret for now by court order. RNZ said the defendant cried on Wednesday as his lawyer Ian Brookie made his opening statements.
Millane's parents have traveled from Britain to watch the trial. Millane's death struck a deep chord in New Zealand, which prides itself on welcoming tourists and where many people travel abroad as well. Hundreds of people attended candlelight vigils after Millane's death, and Prime Minister Jacinda Ardern spoke about New Zealanders feeling "hurt and shame" that she was killed in their country.
Crown prosecutor Robin McCoubrey said Wednesday that CCTV cameras filmed Millane and the man kissing and enjoying their time together on Dec. 1 at a burger joint, a Mexican cafe and then a bar, according to RNZ.
"They were plainly comfortable in one another's company" before entering the man's hotel apartment together, the prosecutor said. He said the morning after the man killed Millane, he did Google searches for "Waitakere Ranges" and "hottest fire," took intimate photos of her body and watched pornography, RNZ reported.
The prosecutor said the man then hired a car and bought a suitcase, stuffing Millane's body into it. He messaged another woman to confirm a date he'd arranged earlier on Tinder, and talked to her about how somebody could get in trouble for manslaughter after rough sex that went wrong.
"He doesn't seem concerned by the presence of a dead body in his apartment but goes up the road to have a date with another woman at a bar," the prosecutor said, according to RNZ. "You may think he's testing out a version of events he may later have to rely on, to see how it sounds."
But Brookie, the defense lawyer, said the man had restricted Millane's breathing with her knowledge and encouragement. "Put simply, this death was an accident," he said, according to RNZ. "He certainly didn't murder her."
The trial is expected to take up to five weeks.