A mother who fatally overdosed her two children with sleeping pills, wrapped them in plastic and left them stored in suitcases for four years knew it was wrong and she should be found guilty of murder, the Crown says.

Hakyung Lee’s trial for the alleged murder of her two children has reached its final stages, with the prosecution concluding closing arguments today.

Lee is on trial in the High Court at Auckland. The trial began with an admission that she had killed daughter Yuna Jo, 8, and son Minu Jo, 6, in late June 2018.

Spiralling into “madness” after her husband’s death, she had given herself and her children what she thought was a deadly dose of a prescription sleeping pill, but she survived, her standby lawyers have said.

They have asked jurors to find Lee not guilty by reason of insanity.

Addressing the jury this morning for the final time, Crown lawyer Natalie Walker reminded jurors of how Lee came to be found in a South Korean psychiatric hospital, four years after she and her children disappeared.

Lee had managed to get in contact with her mother’s pastor, who spoke to her over the phone in June 2022.

Hakyung Lee has admitted she killed her 8-year-old daughter, Yuna Jo (left), and 6-year-old son, Minu Jo, in June 2018. She is on trial in the High Court at Auckland for two counts of murder but her standby lawyers say she is not guilty by reason of insanity. Photo / NZ Police

Walker said the pastor was aware Lee’s two children had been missing for some time, and asked what happened to them.

“To which she replied, ‘I have no children’,” Walker told the court.

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“This was the first in a series of lies told by the defendant, Ms Lee, in relation to the deaths of her daughter Yuna Jo, and son Minu Jo.

“Her mother asked the same question and was told the same lie.”

Walker said she wanted to illustrate to the jury how much of an unreliable historian Lee was.

“The only evidence of her defence - that she attempted suicide and took her children’s lives as she didn’t want them to live without both parents - comes only from her.”

Walker said Lee had provided five different accounts about the deaths of her children since 2022. The prosecutor suggested none was true.

“First is that she had no children. Second, that she had the children but she left them behind in an institution.

“Third, that someone murdered her children, she knew who it was but it wasn’t her. Fourth she was the person who killed her children by drug overdose but was suffering from a major depressive disorder at the time and thought it was the right thing to do.

“And fifth and finally, that voices told her to kill her children and she still thought it was the right thing to do.”

A security photo from Safe Store Papatoetoe shows Hakyung "Jasmine" Lee on the day she hired a storage unit. Her children's remains were hidden at the facility for four years. Photo / Supplied

The alleged premeditated nature of Lee’s actions has formed a major part of the Crown’s argument.

Walker reminded the jury of PlayStation data suggesting the children were alive at the same time Lee was purchasing a courier envelope on June 27, used to apply for a name change the same day.

Receipts showed Lee also went to Mitre 10 and purchased wheelie bin liners and duct tape, which the Crown said could have been used to conceal her children’s bodies.

All this, Walker said, meant it would be fair for the jury to infer the killings were intentional, and not the spontaneous actions of someone severely mentally unwell.

Walker said it was this timeline, which shifted the position of the only defence witness, forensic psychiatrist Dr Yvette Kelly.

During cross-examination last week, Kelly appeared to reassess her findings that Lee was unaware that what she was doing was morally wrong.

However, Kelly maintained that Lee had a disease of the mind.

But Walker said the evidence of Crown witness forensic psychiatrist Erik Monasterio disputed this claim.

Monasterio accepted Lee was likely depressed, and suffering from a complex and prolonged grief reaction.

But he believed she was not impaired, adding that major depression was common in the community.

Walker also spoke of the effort Lee went to, on her own, to wrap her two dead children in three layers of plastic bags.

“Each of which she knotted, then lifted into the next layer, then knotted, lifted into the next layer, then knotted, then lifted and put into the suitcase... it’s quite unimaginable.

“And yet, that’s what she did.”

Walker finished by telling the jury, there were no grounds for an insanity defence.

“It was not the altruistic act of the mother who had lost her mind and believed it was the morally right thing to do – it was the opposite.

“Ms Lee deliberately and in sound mind murdered Minu and Yuna, and the right verdicts are verdicts of guilty.”

Defence closing remarks have begun this afternoon.