After a three-week trial, he was convicted by a unanimous guilty verdict and later sentenced to life imprisonment, with a minimum non-parole period of 17 years.

[7] She had recently graduated from the University of Lincoln[7] with a bachelor's degree in advertising and marketing, and was on a backpacking tour during her gap year.

[8] At 9:00 pm on 1 December, she was seen in Victoria Street in Auckland's central business district, and 15 minutes later she was seen via CCTV at SkyCity.

[10][11] Millane's body was found on 9 December at around 4 pm, off Scenic Drive in the Waitākere Ranges around 19 km (12 mi) west of central Auckland.

Google included Kempson's name in an email it sent to subscribers of its newsletter on trending topics in New Zealand, which claimed that 100,000 searches had been done of the name within the country.

Justice Minister Andrew Little and the New Zealand Bar Association criticised the foreign media, saying the publication of Kempson's name endangered his right to a fair trial.

[30] Prime Minister Jacinda Ardern made a public apology to the family of Millane on 10 December, saying "on behalf of New Zealand, I want to apologise.

[7] Auckland's Sky Tower and Harbour Bridge were lit up in a white ribbon shape from 10 to 13 December to mark her death.

[36] In November 2019, Radio New Zealand broadcaster Colin Peacock criticised the conduct of some foreign media in both the Grace Millane and the concurrent Amber-Rose Rush murder trials, arguing that their breaches of New Zealand name suppression orders threatened the fair trial rights for defendants.

[37] Meanwhile, the Otago Daily Times editorialised that the Millane murder case highlighted that in New Zealand, women were statistically more likely to be victims of violent crimes than men.

[38] In late February 2020, The Guardian's Sian Norris described using "rough sex" as a murder defence as "grotesque victim blaming.

[43][44][45] The prosecution led by Crown solicitor Brian Dickey argued that Kempson had strangled Millane to death following a Tinder date.

Dickey also said Kempson calmly and callously disposed of Millane's body and other evidence, and then created a "labyrinth of storytelling and lies" to cover his tracks.

The Crown also presented security camera footage of Kempson and Millane, including his renting a carpet cleaning machine at the Countdown supermarket in Quay Street.

A Crown expert witness, pathologist Simon Stables, testified that a postmortem examination of Millane's body had found bruising consistent with someone who had been restrained and asphyxiated.

They alleged that Millane had an interest in bondage and sado-masochism and had asked Kempson to choke her during a consensual sex game which went wrong.

[47][48][49] The defence's expert witness, pathologist Fintan Garavan, contested the Crown's autopsy evidence, claiming that her injuries were consistent with a consensual sex act due to the lack of defensive wounds on Millane's body.

Defence lawyer Ron Mansfield also argued that Kempson's claiming to be wealthy and successful stemmed from his personal insecurity.

[60] On 29 June 2021, the Supreme Court dismissed Kempson's application for leave to appeal the verdict, thereby exhausting his legal avenues to overturn his conviction.

[61] The Grace Millane case was the subject of New Zealand journalist Steve Braunias' award-winning 2021 book Missing Persons.