A South Australian man who admitted to killing his baby daughter by shaking her sought to throw authorities "off the scent" of the crime, a court has heard.
WARNING: This story contains content that some readers may find distressing
Nicholas Trevor Masling, 33, previously pleaded guilty in the South Australian Supreme Court to the manslaughter of his daughter — who cannot be identified for cultural reasons — at their Whyalla Stuart home in June 2016.
Today, Supreme Court Justice Anne Bampton heard sentencing submissions.
Masling, who has seven children to four different women, was in a "bad mood" after smoking cannabis until the early hours of June 5, 2016, the court heard.
He "violently" shook his six-week-old baby when her crying woke him up at 11am and he was tired.
The baby girl, who was made to sleep in a pram as a bed, turned purple and became unresponsive after being shaken.
She was taken to the Whyalla Hospital not breathing and with serious injuries.
The child was resuscitated and transferred to Adelaide's Women's and Children's Hospital, where she died 17 months later in November 2017.
Justice Bampton questioned why Masling was not forthcoming with medical staff about the actions that led to the child's injuries in the months after the crime.
The court heard he had a phone conversation with his mother in which he said he wanted to throw authorities "off the scent" of his actions, after being questioned by hospital staff and police.
The prosecution said Masling was more concerned about the implications for his life than his daughter's health.
A lawyer who spoke on behalf of the baby's mother said the girl's death had mentally, physically and emotionally impacted her, and she felt as if she had lost five years of her own life.
Victim also had rib and leg fractures
Medical experts said the inflicted brain injuries left the child in a "vegetative state" in which she was unable to swallow or breathe properly.
As well as critical brain injuries, the court heard the newborn had notable rib fractures and two leg fractures which pre-dated the incident.
She had bruises on the sides of her head, which medical experts said were likely from an adult gripping onto her.
Doctors said the additional injuries were not from CPR, which was performed on the baby the morning she was shaken.
Masling's lawyer told the court that, despite trying to conceal the crime, Masling was genuinely remorseful.
"There was an attempt by him to distance himself from what had happened," Steven Millsteed QC said.
"But that is not inconsistent with him being genuinely upset and remorseful over what had happened to the baby.
"His distress was evident when the medical personnel were at the house."
The court was also told the mother was the child's primary caregiver.
"He had very little to do with the upbringing of the child," Mr Millsteed said.
"She (the mother) was the primary caregiver."
The court previously heard Masling was recorded on the phone making admissions, and expressing remorse.
Police had previously said the baby girl "deserved better".
"[She] is one of our most vulnerable citizens," Detective Inspector Greg Hutchins said in 2017.
"At the time police responded to the Whyalla Stuart address, she was only 41 days old.
"She was a little fighter and she fought a long time."
Masling will be sentenced at the end of March.
