"Auckland Crown Solicitor Brian Dickey is addressing Justice Simon Moore, ahead of sentencing.
Dickey said there was a "high level of brutality, depravity and cruelty" in Grace's murder, therefore the killer should spent at least 16 years in prison.
He said there were a number of aggravating factors, such as the brutality and callousness he showed after killing her, including searching for *advertiser censored* and taking intimate photographs.
"Manual strangulation, by its nature is a very close quarters, personal and callous thing to do to another person, and to kill them."
"The very act of strangulation is a personalised way to kill a person."
The intimate photos taken of Grace, shortly after her death shows the killer eroticised this death, Dickey said.
He said the defence maintains the photo wasn't taken after her death, but he argues that submission doesn't hold much weight.
"There is of course, the events afterwards ... the way the defendant went about his life, trying to date other women and trying to cover his tracks ... this is not rough sex gone wrong, this was a violent death," he said."
Grace Millane: Murderer to be sentenced for killing British backpacker