A woman has told how she went on a date with Grace Millane's killer days after he murdered the British backpacker.
And she revealed how the twisted killer appeared to be rehearsing his story by talking about a 'friend' who had killed a woman during rough sex.
She believes she could have become his next victim has she met him in the evening.
This week this man, who strangled Ms Millane the day before her 22nd birthday, was jailed for a minimum of 17 years in New Zealand.
His defence that she'd died during rough sex was rejected.
Grace was murdered in a hotel room in Auckland on December 1, 2018.
But as her body was kept stuffed in a suitcase, her killer went out on another date.
A woman had met the killer in a bar a few weeks earlier and had been chatting to him online.
“He was an Australian so we talked Aussie things. He seemed like a nice, normal guy...,” she told the BBC.
They arranged a date but he got “really persistent” texting her multiple times a day trying to bring it forward.
She said he messaged her around 9am, the morning after Grace's murder saying 'good morning, how are you?' then again at 10.30am saying it was fine if she didn't feel like going on a date.
But she agreed to meet him in a bar where he claimed his mates were police officers and his best pal was coming over to New Zealand to be a crown court prosecutor.
“I think it was definitely on his mind and I think he was, in a weird way, trying to process something of what had happened, what he had done, with me,” she said.
“It was a very strange insight into what someone's brain does after they do something like that.
“He had obviously been thinking about policemen, bodies, ways people can be killed, prosecution, justice and the court system and it just came out in a very strange way.”
He told his date how police were having a “tough time because of bodies going missing in the Waitākere Ranges”.
This is where Grace's body was later found.
And he told her: "Police dogs can only smell four feet deep so if they are buried deeper than that, they can't find them'.
She said: “Then he told me this really bizarre story.
“He told me about a guy he knew in Australia who had consensual rough sex involving strangulation with his girlfriend but ended up accidentally killing her.
“It was an accident – things went wrong and he was really upset by that because he loved her – but the guy got done for manslaughter and was sent down for a long time."
The woman said he told her: 'It's crazy how a guy can make one mistake and go to jail for the rest of his life'.
“He could see I was a bit uncomfortable and tried to talk about more mundane things...” she said.
His strange behaviour set her alarm bells ringing and she walked away – despite her car being in the same direction as his.
“He was also a lot bigger than me so if something went wrong I knew I wouldn't be able to defend myself," she said.
She added: “What we know now is this could have been him testing out his story on me.
“I do think if it had been a date in the evening potentially I could have been a victim."
She told the BBC she was speaking out to warn women to think about their safety when on dating apps.
At his sentencing, his victim's mum, Gillian Millane, confronted him via video link from her Essex home.
She said her daughter had “died terrified and alone in your room" and she thinks about the "terror and pain" she must have experienced.
The man, who cannot be named for legal reasons as he is facing further legal action, held his head in his hands as he listened to the impact his "barbaric actions" have had on Grace's family.
Her mum told how she regularly sprays Grace's perfume and attends weekly counselling sessions.
"I am absolutely heartbroken that you have taken my daughter's future and robbed us of so many memories that we were going to create.
"...I will miss my darling Grace until my last breath."
DI Scott Beard from New Zealand police said of Grace's family after the hearing: “They will forever have a life sentence” and added: “Strangling someone for five to ten minutes until they die is not rough sex...”
Grace from Wickford in Essex, was six weeks into a backpacking "trip of a lifetime" after recently graduating from the University of Lincoln.
Her cousin, Hannah O'Callaghan, later said the sentencing of her killer this week will not bring closure to the family.
"We've lost Grace," said Hannah O'Callaghan. "The sentence will not change the fact that Grace is gone."
