Warning: This story contains evidence from the trial which some readers may find extremely upsetting.
A top psychiatrist says there is no evidence of insanity or postpartum depression when Lauren Dickason killed her children.
Earlier on Tuesday, the psychiatrist revealed to the jury, Lauren changed her reasoning for killing her children six months after he first interviewed her.
In the murder-accused mum's interviews with Dr Monasterio, she expressed anger towards the children - anger he said she later denied after she "made sense" of the situation.
But Dr Monasterio believes Lauren was angry when she killed her three daughters one by one.
"Why would somebody that would kill their children not say to you, I did this because I was certain that they would come to serious harm and this was that harm that I was concerned about," he told the jury on Tuesday.
Over the course of the trial, the jury will hear from five mental health experts who assessed Lauren after the killings.
Last week, the defence called a leading expert in infanticide to the stand who said Lauren's mind at the time of the killings was disturbed by a disorder that was a consequence of childbirth. Therefore, she believes Lauren was incapable of knowing the act was morally wrong.
Lauren is accused of murdering her little girls - 6-year-old Liané and 2-year-old twins Maya and Karla - at their Timaru home on September 16, 2021.
The children were found dead by their dad Graham Dickason after he returned home from a work function.
Lauren has admitted to killing her children by smothering them to death but pleaded not guilty to murder. Her defence is arguing insanity and infanticide - that she did not know what she was doing at the time of the killings.
However, the Crown alleges Lauren is guilty of murder, saying she was aware of her actions before, during and after the crime.
The trial continues for its twelfth day at the High Court in Christchurch in front of a jury of eight women and four men.
Expert opinion
Crown witness Erik Monasterio has told the court, in his opinion, Lauren does not have an insanity or infanticide defence.
Dr Monasterio, the former director and clinical director of Canterbury District Health Board area mental health, has done thousands of mental status examinations over his career.
He believes Lauren's psychiatric diagnosis in the leadup to and at the time of the alleged offending is "major depressive disorder recurrent with moderate to severe severity".
When ruling out the infanticide defence, Dr Monasterio pointed to Lauren's history of mental health.
He said the effects of pregnancy and demands of motherhood likely contributed to her depressive disorder but noted her depression started in her teenage years.
"It occurred well before the defendant's pregnancy… Postpartum means after birth, her depression was already there."
From November 2020 to June 2021 she experienced a full remission of symptoms despite weening herself off anti-depressants, Dr Monasterio said.
In July 2021, there was considerable deterioration in Lauren's mood but it wasn't caused by childbirth but rather by the COVID-19 lockdown, riots in South Africa and immigrating to New Zealand, Dr Monasterio believes.
"There is no evidence, at this current episode of depression, as pregnancy, post-partum or lactation cause. There is no clear evidence that the defendant experienced any symptoms of psychosis associated with this condition," Dr Monasterio said.
His reasoning against insanity was throughout her depression, Lauren was able to navigate the complexities of immigration and get the family to New Zealand. She organised the shipping container, thought to bring a vacuum cleaner with them to MIQ and packed her children's bags with meticulous care.
In Timaru, Lauren bought stationary, opened bank accounts and corresponded with friends back in South Africa. Dr Monasterio was particularly impressed with Lauren's correspondence with immigration emails.
"It may seem like quite a simple task, to us - but these are the objective measures that we have to determine the impairment," he said.
Dr Monasterio also noted how Lauren was able to give consistent and chronological accounts of what happened before and during the killings.
"She maintained a high level of cognitive function."
Dr Monasterio said the defendant did not give an indication that she killed the children to protect them from harm, spare them suffering or because she felt that they would be better off dead.
He recalled how Lauren told the police after the alleged offending that she choose to kill Karla first because she "was really horrible" to her lately, suggesting anger and frustration towards this twin was likely to have contributed to the offences.
Dr Monasterio also described how Lauren had an "awareness" during the alleged murders which are estimated to take around 20 minutes, including checking their vital signs. He also said the alleged offence required some degree of pre-planning, noting Lauren had previously thought about the method of killing she had used back in South Africa.
He said there is no evidence Lauren was incapable of understanding the moral wrongfulness of her actions.
"Ultimately, the credibility of the defendant is not a matter for expert witness but for the court," Dr Monasterio said.
'About to explode'
Dr Monasterio interviewed Lauren for a total of nine hours over four occasions - three in October 2021 and once in April 2022.
Earlier on Tuesday, the forensic psychiatrist said Lauren reported anger and frustration towards her children, particularly the twins.
The day before Lauren is accused of murdering her children, she had strong thoughts of wanting to harm the twins, he said in court on Tuesday.
Lauren told Dr Monasterio she needed space from the twins so Graham took the children to the park while she cooked dinner, he said.
She said she felt so angry and had thoughts about harming the twins, Dr Monasterio said.
"I was like a bottle of coke that had been shaken and was about to explode," Lauren told the psychiatrist.
She then went to bed, without having a shower or getting changed from her day clothes and cried for an hour, he said.
Lauren also discussed with Dr Monasterio want happened on the day of the killing.
"Her feelings about life in Timaru remained very negative. She reported that they had made a mistake coming to New Zealand," Dr Monasterio told the jury.
Lauren recalled the encounter with a boy taking photos of the children at the park and noted how her children cried out for Graham when he left them to look at some birds in the gardens.
"I felt like a failed mother. My children always preferred Graham. They didn't want to be with me," she told the psychiatrist.
Lauren described how her children demanded more food after they finished their dinner.
"I was so worried I was going to give one of the kids a bloody good hiding," she said.
After dinner, the children got ready for bed and Graham left for a work event, kissing Lauren goodbye and patting her on the shoulder.
But as soon as he left, Lauren said the children started playing up and felt an overwhelming feeling of being overworked, Dr Monasterio said. The idea of having to manage the kids, live in a small, cold place and deal with immigration and COVID-19 became too much.
"I didn't feel like myself… I couldn't see myself going through another day," she said.
Lauren told Dr Monasterio all she wanted was some quiet and not to feel like a bad parent anymore.
Flashes of the children playing with cable ties in South Africa came to her mind and she remembered seeing the ties in the garage - so she grabbed them and asked the children to lie in bed and killed them.
In the lead-up to the killings, Dr Monasterio said Lauren reported feeling deeply depressed and had a fluctuating sense of hopelessness and pessimism about the future. However, she had moments of optimism, including after attending the BBQ with Graham's work colleagues and when Liané said she enjoyed school.
She said she was not concerned the children wouldn't be able to adapt to New Zealand, he said.
He said Lauren acknowledged she had anger and frustration towards the twins as they would play up and not listen - saying it has to stop.
"She reported that she decided to kill the children," Dr Monasterio said.
"The defendant described awareness of her actions throughout the offences that lasted for around 20 minutes."
He said Lauren didn't call Graham because she said she "wanted it all to finish".
Months later, Lauren's reasoning changes
Dr Monasterio next interviewed Lauren six months later in April 2022.
He told the jury Lauren reported that after spending time thinking, she realised she killed her children to protect them.
"I couldn't leave them behind. They would suffer too much," she told Dr Monasterio. "I was very, very sick. I have never been that depressed."
Lauren continued to deny experiencing psychosis at any time or preplanning the alleged offences, claiming her actions were largely impulsive.
She told the psychiatrist she did not report the reason why she killed her children in earlier interviews because, at the time, she failed to understand it and only made sense of the situation in recent months.
"I was in a muddle," Lauren said.
Lauren denied experiencing significant anger towards kids despite messages on WhatsApp claiming otherwise, Dr Monasterio said.
"Why would somebody that would kill their children not say to you I did this because I was certain that they would come to serious harm and this was that harm that I was concerned about," Dr Monasterio said.
"Now I have not found evidence for this in my examination of the defendant or in my consideration of all the additional sources of information."
He believes there is zero evidence of psychosis.
The defence has begun its cross-examination of Dr Monasterio - this will continue on Wednesday.
Where to find help and support:
- Shine (domestic violence) - 0508 744 633
- Women's Refuge - 0800 733 843 (0800 REFUGE)
- Need to Talk? - Call or text 1737
- What's Up - 0800 WHATS UP (0800 942 8787)
- Lifeline - 0800 543 354
- Youthline - 0800 376 633, text 234, email talk@youthline.co.nz or online chat
- Samaritans - 0800 726 666
- Depression Helpline - 0800 111 757
- Suicide Crisis Helpline - 0508 828 865 (0508 TAUTOKO)
- Shakti Community Council - 0800 742 584
