WARNING: This story contains graphic and sensitive content.

Police analysed hundreds of thousands of messages sent and received by Lauren Dickason as they investigated her for the alleged murder of her three children.

The Crown says some of the messages support its case that 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”.

Dickason, 42, is on trial in the High Court at Christchurch charged with murdering her daughters Liane, 6, and 2-year-old twins Maya and Karla.

She admits to smothering the children to death but has pleaded not guilty to the murder charges by reason of insanity or infanticide.

While the Crown acknowledges Dickason suffered from depression, it maintains she knew what she was doing when she killed the girls.

Lauren Anne Dickason appears in court on the first day of her two-week trial for the murder of her three children.

The defence refutes that and says the woman was “very unwell” and while those close to her were worried - no one recognised how unwell she was “until it was too late”.

“This tragic event happened because Lauren 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,” Dickason’s lawyer Kerryn Beaton KC told the jury.

As part of the police investigation - dubbed Operation Royal - a detective was tasked with analysing the content of Dickason’s phone.

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He went through more than 330,000 messengers sent and received by Dickason from her husband, family and friends.

In many of the messages, Dickason reveals her frustrations about her children and their behaviour.

Hundred of the messages are to be read to the jury in support of the Crown case today and Monday.

In many, Dickason speaks about having “rough” days with her children, being overwhelmed, emotional, stressed and tired and crying or being on the verge of tears.

The messages span from 2016 to several hours before the children were killed - through the pandemic and lockdowns in South Africa, their emigration process, the family’s isolation period before getting on the plane to New Zealand, managed isolation in Auckland and getting to Timaru.

They are all dated and some show message threads to give context to the jury.

Some of the messages Dickason wrote show her struggle and frustrations as a mother, and with her long-term depression and anxiety - which the jury have heard much about this week.

They include:

• I think God is trying to torture me by giving me the noisiest kids ever.
• They’re making me crazy.
• Liane … kept me awake until 3am but I sent her to school otherwise I would strangle her. She moans all the f**king time.
• My heart is very sore because I love my kids so but at the moment I just wish for a day alone.
• (The children) sniff me out wherever I go and if they can’t find me they start screaming hysterically.
• Every morning and during the day is like wartime with my depression.
• Three kids has really killed all the passion and a lot of the happiness.
• I almost called you because I was suicidal. Please don’t tell Graham.
• These kids really tire me out physically and emotionally.
• Other people make it all look so easy that I feel abnormal because I perceive it as intense and I struggle to enjoy it (being a mum to twins).
• Graham and I are despondent, babies don’t want to sleep at night, Liane doesn’t get any attention after the other two take it all. It feels like my fuse is just so short the whole time and I want to explode over the tiniest things. Graham and I don’t get time along, we barely talk to each other ... I feel like I just want to run away.
• FFS I am losing it today. Told Graham I am just coming home to cry about everything.
• This whole NZ is really stuffing with my mind right now. It’s like reliving infertility all over again, with people asking you every time you see them
• Tonight Graham and I decided that our children will not abuse and scream at us and hit us any further. From one on they will get hidings and all their nice things will be held back until they start showing some respect. Tonight they threw corn at me and said the meat is disgusting. Then they hit me when I told them off. Maybe the twins are just in terrible twos but fuck, they are going to kill me. I was so angry tonight, I was haking.

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

In a message to another woman, she said she needed “help with learning to cope with motherhood”.

“I am under the care of (a doctor) for depression but even though the meds work most of the time I get overwhelmed so easily and the anxiety gets so bad I cannot eat, sleep of function properly. I think most of it is caused by frustration and boredom as I look after the babies during the day and I feel as if I no identity of my own.

She described having three young children as “a hard hard season”, saying there was “no time to just sit and talk” with her husband because “there is always a kid in the middle”.

Dickason spoke a lot about her concerns about covid - and her fears were exacerbated after several members of Graham Dickason’s family died from the virus.

“Covid fear is just too much at the moment,” she said to one friend.

“I have this intense fear that something like that will happen to us,” she told the partner of one of the relatives who died.

There were also a number of positive messages sent by Dickason talking about being happy and “super excited” about their “new adventure” in New Zealand.

She felt the move would be “scary” but she was “looking forward to a simpler life”.

She also spoke often about how much she loved her “beautiful” kids and husband.

“I love you, thanks for being such a wonderful daddy to our babies,” she messaged Graham Dickason in 2020.

“Thanks babe, I am just doing my best - thanks that you keep them alive, and me too,” he replied.

Graham Dickason messaged his wife often to show support and remind her how much he and the girls loved her - particularly around the move to New Zealand and the massive work she was doing to pack up their lives in South Africa and organise their new one.

“This process will have its bolts and holds and we have to work through them,” he said.

“Together is better than alone ... I know you feel in limbo ... our situation is still very far from being hopeless. we have so much to be thankful for.”

In June 2021 the Dickason family’s move to New Zealand was confirmed and approved.

“Timaru here we come, she said - immigration in the middle of a pandemic, I am literally shaking... so excited, there is no covid there, I am so happy about NZ” she siad.

She was worried about spending two weeks in a hotel in managed in isolation and said her kids were “f**king crazy” - but did not appear reluctant to leave South Africa.

“To be honest I can’t wait to get out of this dammed country - I will fly tomorrow even if I can’t say goodbye to anyone or bring anything with me,” she told one friend.

“We want to give our three little princesses for whom we have prayed so long and hard, the adventures of a lifetime,” Dickason told another woman.

Dickason for a long time before moving had voiced concerns about unrest and violence in South Africa.

She told friends the threat and fear of looting made her “stressed and irrational”.

“My nerves are f**king finished. And now my husband thinks I’m crazy,” she said.

She told another friend they were sleeping with a 9mm calibre firearm beside the bed.

“We want a better quality of life,” she said of moving to Timaru.

She said the lead-up to the move was the hardest period in her entire marriage but assured friends “we know where we are going and quitting is not an option for us”.

The reading of the messages is set to take some time and will continue today and at least through Monday.

The trial is set for about four weeks before Justice Cameron Mander and a jury.

The Crown will call more than 30 witnesses, including five experts on insanity and or infanticide.

The defence will then open its case and is expected to call a number of witnesses, including its own experts, to give evidence about Dickason’s mental state.