WARNING: This story contains graphic and sensitive content.

A psychiatric expert giving evidence at Lauren Dickason’s High Court murder trial has been grilled today by the defence about her process and findings.

But she maintains the woman who confessed to smothering her young children to death was not insane at the time.

And she had told the court that it may have been “premeditated”.

Defence lawyer Kerryn Beaton KC has questioned whether a court-appointed health assessor had a good enough rapport with Dickason and whether she considered all of the information available to her in forming her professional opinion that the accused was not insane when she killed her children.

Dr Simone McLeavey maintains she is “comfortable and confident” in her opinion and that she undertook “sufficient” work to form her opinion that Dickason does not have a defence of insanity or infanticide.

Dickason admits she killed her daughters Liané, 6, and 2-year-old twins Maya and Karla in September 2021.

But she has pleaded not guilty to three charges of murder and has mounted a defence of insanity or infanticide.

Lauren Anne Dickason allegedly killed 6-year-old Liané, and 2-year-old twins Maya and Karla at their Timaru home on September 16.

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She is on trial in the High Court at Christchurch before Justice Cameron Mander and a jury.

The trial is now in its fourth week and is expected to run into next week.

So far, extensive evidence has been presented about the 42-year-old’s life - her upbringing, marriage, the gruelling fertility treatment she underwent to have children and her long battle with anxiety and depression.

The jury watched footage of police interviews with Dickason and her husband Graham - who found his children dead in bed and his wife in need of medical attention when he returned from a work function.

Psychiatric experts began giving evidence last week and that continued today.

The jury will hear from five experts in total - three are being called for the defence and two for the Crown.

On Thursday Dr Simone McLeavey - a court-appointed psychiatrist who was called upon to assess Dickason soon after her arrest - gave evidence for the Crown.

McLeavey - who oversees a forensic rehabilitation unit at HIllmorton Hospital - said while Dickason a “mentally disordered woman with a vulnerable personality” and had a “limited capacity to manage stress” - she did not believe she was insane at the time of the alleged murders and has no infanticide defence.

“It remains my opinion that the defendant’s disease of mind did not seriously impair her reality, testing ability and capacities thereof such that she did not know the alleged offending was morally wrong, having regard to the commonly accepted standards of right and wrong,” she said.

“I am of the opinion that this is a tragic case where a mentally disordered woman with a vulnerable personality killed her children in the context of the situation which she perceived to be beyond her limited capacity to manage stress ... in addition to underlying mental illness.

“Taking these factors into consideration, on the balance of probability, I am of the opinion the defendant would not be eligible for an insanity defence.”

Lauren Dickason was remanded to Hillmorton Hospital after her arrest and first appearance in court. Photo / NZ Herald

She said while Dickason had an “abnormal mental health state”, she “cannot unequivocally subscribe” to the theory that the “balance of her mind was disturbed by reason of her not having fully recovered from the effect of giving birth”.

That was partly because of Dickason’s “propensity for depression” dating back to when she was 15 years old.

“It is my opinion on the balance of probability, there is no evidence that the defendant has an infanticide defence available,” she said.

Beaton began cross-examining McLeavey on Thursday and continues today.

She has questioned the doctor at length about her forensic experience, how she was selected to undertake the assessment of Dickason, how she carried out that work and what other information she considered when forming a final opinion.

McLeavey remained firm that Dickason “was suffering from a recurrence of a major depressive disorder” but was able to function in her daily life.

That, in her mind, supported her conclusion.

‘Undoubtedly’ depressed, and angry - but not insane says Crown expert

McLeavey last week said she disagreed with any suggestion Dickason killed with an “altruistic motive”.

Defence expert Dr Susan Hatters-Friedman - a forensic and reproductive psychiatrist - had earlier told the jury Dickason’s actions were that of a parent killing “out of love” rather than out of anger or hate.

“She had been severely depressed and had developed psychotic thinking,” she said.

“She attempted to kill herself … she viewed the world as dangerous for her children to grow up in.

“She saw a joint suicide and filicide as a way out of this for her beloved children and herself … She thought she was getting her children to safety.”

But McLeavey did not believe that was the case.

“Any altruistic motivation was, in my opinion, fueled more so by a need for control and anger,” she said last week.

She said that stemmed from a “vulnerable” Dickason finding the thought of her husband remarrying after her suicide - and another woman parenting her children - untenable.

Beaton quizzed her on that further today, asking what led to her form that conclusion.

She said it was Dickason’s admission she killed Karla first because the child had been “demonic, screaming, feisty”.

“She was angry and that was why she targeted Karla in the first instance,” she said.

McLeavey said Dickason was “undoubtedly significantly depressed” but she was “able to maintain the responsibilities of daily living” which did not point to insanity.

“Her depression didn’t worsen... her perception of the situation worsened,” she said.

“She was distressed at that moment in time... She had a negative distortion of reality... which would be not uncommon in depression.”

Under cross-examination, McLeavey also remained firm on her view that Dickason was not experiencing psychosis when she killed the girls.

She said it was ‘unusual to miss’ psychosis symptoms.

“It would be exceptional for psychosis not to be detected if in fact, it was present,” she said.

“Grieving would not in itself mask psychosis... she was clinically depressed... her physical health was compromised.... not lacking of insight she was very self-aware of the situation she found herself.

“She was indeed insightful... she was very cooperative.

“I believe there was self-awareness sin the lead-up to the (alleged) offending... and she remained insightful.”

McLeavey said she initially noted that the killings were “impulsive” but her opinion had since changed and she believed they were “possibly premeditated”.

She said the fact Dickason had carried out Google searches about overdosing her children was “compelling”.

Paired with Dickason’s earlier admissions she had thought of hurting or killing the girls, she felt there could have been a degree of planning.

“He had a very clearly informed intention to harm the children,” she said.

“There was more than ideation… there was planning… there was consideration for specific means and methods.

“There was a loss of control, to act on the thoughts.”

Beaton argued the alleged offending was “entirely impulsive” and her client “hadn’t planned it at all”.

The cross-examination continues.

After the expert evidence is complete the jury will hear closing addresses from the Crown and defence.

Then Justice Mander will sum up the case in its entirety and instruct the jury on its role - and how it should work towards reaching a verdict.

The jury will then be sent to deliberate.

It is expected the trial may not reach that point until next week.

The King v Lauren Anne Dickason - the trial so far:

The Crown alleges Dickason murdered the children in a “calculated” way because she was frustrated, angry and resentful of them.

It acknowledges Dickason suffered from sometimes-serious depression, but maintains she knew what she was doing when she killed the girls.

Last week, Crown prosecutor Andrew McRae alleged Dickason was an angry and frustrated woman who was “resentful of how the children stood in the way of her relationship with her husband” and killed them “methodically and purposefully, perhaps even clinically”.

The defence says Dickason was a severely mentally disturbed woman in the depths of postpartum depression and did not know the act of killing the children was morally wrong at the time of their deaths.

Further, it says she was “in such a dark place” she had decided to kill herself and felt “it was the right thing to do” to “take the girls with her”.

Lauren Dickason during her police interview. Photo / Pool

The Crown: The evidence will firmly point towards ‘methodical’ murder

Crown Prosecutor Andrew McRae said there was no question the case was tragic and that Dickason was mentally unwell.

“There is no doubt in this case that the defendant was responsible for killing,” he said.

“The issue in this case, is whether Mrs Dickason intended to kill her children out of frustration, anger for their behaviour, or resentment for how they got in the way of her relationship - or whether in fact, her state of mind at the time was such that she must have been insane or have the partial defence of infanticide.

“The Crown says there was anger here, and she methodically killed all three of her children.

“The Crown say that there is no medical defence here, and that the evidence will firmly point towards murder.

“This is going to be a difficult trial and one that you’re going to need to listen very carefully to the evidence is presented.

“But I stress to you - this is not a trial by expert. The expert evidence will be a part of the material that you will need to make your decision in this case.”

McRae said trials were not “a search for excuses, or even reasons”.

“A trial is a search for the truth - and the Crown says that the truth is that while the defendant was likely suffering from a major depressive disorder, she knew what she was doing before, during and after she acted methodically and purposefully, perhaps even clinically and what she did.

“She knew, the Crown say, what she was doing was morally wrong, and continued on her course, in any event.

“Your task is to determine the truth of what happened, and more specifically the truth about Mrs Dickason’s state at the time that she killed her children.”

Crown Prosecutor Andrew McRae. Photo / George Heard

He said Dickason had “a lifelong propensity towards anxiety and perfectionism.

“[She was] always demanding very high standards from herself, and a tendency towards self-criticism for any actual or perceived failure to meet those standards.

“The Crown says the unpredictable nature of children and their behaviour clashed strongly with their personality traits.

“The Crown case is that the defendant was angry at her children on the night - she was angry at them for not listening, and for jumping on the couch after her husband had left the house.

“She described the pressure she was under and this made her snap. The anger was bubbling over from many aspects of her life, the ongoing behaviour of the children but, also, the Crown says she was resentful of how the children, that they stood in the way of her relationship with her husband.”

McRae said the jurors would naturally want to find “a palatable motive to explain the inexplicable.

“But the Crown says that the motive was simple here that she snapped.

“It was the straw that snapped the camel’s back, she was under pressure, and when the children misbehaved her anger at the children took over and she killed them.

“The cause of this, the Crown say, was not a disturbance of the mind from childbirth, nor was she insane.”

The defence: insanity or infanticide - Dickason’s diseased mind to blame

Dickason is represented by a team of lawyers led by Kerryn Beaton KC.

On the first day of the trial, Beaton briefly outlined the defence case.

“Lauren Dickason was a loving mother and wife. She loved Liané, Maya and Karla very much and yet she killed them - and as you’ve just heard it was violent and it was prolonged.

“But afterwards she put her girls in their beds, she tucked them in with their soft toys, she covered them up with their blankets and then she took an overdose of pills trying to kill herself, but she failed.

“This is brutal. It’s confronting. It’s difficult to hear and to imagine… what Lauren Dickason did was shocking and horrifying and you might well be thinking what mother could do that to their children?

“A terrible person is what the Crown would have you believe, who resented her children and who wanted them gone.

“But the truth is that Lauren Dickason is a woman who longed to be a mother who went through 17 rounds of IVF to have her three daughters. She wanted those children very much and she loved her family.

“But on the 16th of September 2021, Lauren Dickason was experiencing a major depressive episode of such severity that not only did she think she had to kill herself, she thought she had to take her girls with her.”

Kerryn Beaton KC is representing Lauren Dickason at her murder trial. Photo / George Heard

Beaton said it was undeniable her client “sometimes struggled with being a mum.

“She was sometimes angry or irritated with her kids, her husband, with motherhood, she complained about them.

“She ranted to her friends, having twins was hard.”

Beaton said Dickason battled with her mental health and " thoughts and feelings of harming her children” over the years.

“She was scared by those thoughts and feelings and in 2019, she saw a psychiatrist for help,” she revealed.

“But you’ll hear that despite those thoughts and feelings, she was loving, she was protective of her children, including on the day they died, she actually took great care of her children.

“She always tried to do what was best for them. They were not mistreated or abused until the night of the 16th of September 2021.

“Despite what the Crown would have you think, Lauren Dickason is not a bad person - she’s intelligent, she’s educated, she’s caring, she’s loving, she’s a much-loved daughter, sister and friend.

“And you’ll hear that by the 16th of September, she wasn’t communicating well with her husband or her family and she was very unwell and while those close to her were worried about her, tragically, no one recognised just quite how unwell she was until it was too late.”

Beaton said the defence evidence would show the “tragic event” happened because Dickason was “in such a dark place so removed from reality.

“So suicidal, so disordered in her thinking that when she decided to kill herself that night, she thought she had to take the girls with her,” she said.

“These issues will crystallise for you during the trial.

“You will hear that no one who knew her would ever have thought she could do this to her babies. But she did.”

She said after Dickason killed the girls her “intention was to go to bed… and to never wake up”.

“The question is why she did that,” she posed.

“All three defence experts say her mind was disturbed by reason of her postpartum depression arising from childbirth.

“All of the defence experts agree that there was an altruistic motive… That means that Lauren killed her children out of love.

“In her mind, she was killing them out of love - she was killing herself and she didn’t want to leave the children… she was so sure this was the right thing to do she persisted.”

Toohey said the decision to kill herself and the children was “spontaneous.

“She believed life was no longer worth living, for either her or her children.

“She decided to kill herself and she felt that they were all better off dead. Lauren felt inadequate as a mother, she found it hard to cope…”

Toohey said Dickason was “severely” unwell and had been effectively spiralling into a deep depression with suicidal thoughts for months.

“This is about postpartum depression and a mother who killed her children,” she said.

“She did not want to leave her children without a mum… she also did not want her children to suffer from having such a bad mother.

“This was an impulsive decision - she did not plan it.”

Toohey said Dickason was “a highly intelligent capable person”, a doctor by profession whose “entire vocation in life is geared toward saving lives.

“Why did she kill her three beautiful girls, who she fought for years to get through brutal IVF treatments - her girls who she loved and protected?

“The answer is that Lauren was severely mentally unwell on that night. There is no question about that.”

In the weeks leading up to the family moving to New Zealand Toohey said Dickason’s family and husband were “all desperately worried” about her.

On the day of the alleged murders her client was “so deep into her depression, removed from reality… that she decided to die and take her daughters with her.

“If you find that Lauren’s mind was disturbed at the time, this happened due to postpartum depression, then this is not murder, it’s infanticide,” Toohey said.

“And if she didn’t know what she was doing was morally wrong that night, then she is not guilty of murder or infanticide, that is insanity.”

SUICIDE AND DEPRESSION

Where to get help:
• Lifeline: Call 0800 543 354 or text 4357 (HELP) (available 24/7)
• Suicide Crisis Helpline: Call 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: Call 0800 376 633 or text 234
• What's Up: Call 0800 942 8787 (11am to 11pm) or webchat (11am to 10.30pm)
• Depression helpline: Call 0800 111 757 or text 4202 (available 24/7)
• Helpline: Need to talk? Call or text 1737
If it is an emergency and you feel like you or someone else is at risk, call 111