She admits smothering the children to death, but has pleaded not guilty to the murder charges by reason of insanity or infanticide.
Since Monday, the jury has heard extensive evidence about the alleged murders, how Graham Dickason found his children dead in their beds and the family’s life leading up to the terrible day.
Dickason’s long history of depression and anxiety has been discussed in court at length, as well as her gruelling fertility journey that included having to give birth at 18 weeks’ gestation to a baby girl that did not survive.
Today the jury is hearing from those to arrive first at the tragic scene.
Graham Dickason had been at a work function and when he arrived home he found the little girls tucked under blankets in their beds.
They had been smothered to death.
Having only been in New Zealand a short time he was not sure of the emergency services number so called his colleague Mark Cvitanich.
This morning Cvitanich’s statement was read in court by Crown Prosecutor Andrew McRae.
He explained that Cvitanich was the clinical director of orthopaedics at the South Canterbury District Health Board and had been involved in employing Graham Dickason for a role at Timaru Hospital.
He first met the family when they arrived in the small town, letting them into their pre-arranged accommodation across the road from the hospital.
In the following days a welcome barbecue was held for the family and Cvitanich and a number of other colleagues and their partners attended.
Nothing seemed amiss with the Dickason family, Cvitanich said.
The night the girls died Cvitanich had attended the work function with Graham Dickason.
“I went back and checked their airways and pulses…This is when I observed the two children in the beds had zip ties around their neck, and they had been cut.
“There were several [ties], connected.”
Turnbull confirmed there were no signs of life and went back to Dickason.
The jury was shown photographs of the house including the cut zip tie on the hall floor and Dickason lying on the bed, in her pyjamas with bare feet.
Photos of the bedroom where the girls were found were not shown.
The jury earlier heard that Dickason tried to asphyxiate the girls with the ties, but failed and smothered them to death with blankets.
Both Schrader and Turnbull were visibly upset while giving their evidence, pausing often as they recalled what they saw and did the night of the alleged murders.
Hato Hone St John paramedics also gave evidence today.
Hayley Hooper said Dickason was “in a catatonic state” but her vital stats were normal and there were no life-threatening injuries.
She confirmed Dickason walked - albeit “stumbling” - from the house, down the driveway and stepped into the ambulance.
Hooper said when she checked the children there were “significant signs of strangulation”.
“There were no heart sounds,” she said, explaining how she checked the girls one by one for any signs of life and chance of resuscitation.
Hooper’s partner Alexandra Andrews said Dickason looked “vacant” when she spoke to her.
“Her speech was slurred... incomprehensible,” she explained.
“The patient had a cut on her left wrist which she had covered up with a small plaster... I asked if she had done it to herself and she said no... it was not bleeding and it wasn’t a concern to me.”
Andrews said there were no signs of an overdose at the house nor any signs of serious physical trauma.
“The patient was able to walk... she seemed to know where to go... the patient remained quite rigid but she was able to walk quite quickly and with minimal assistance.”
She asked Dickason if she knew where she was going and why - and the woman replied “yes”.
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.