A baker who murdered his baby daughter by shaking her and throwing her onto the floor because he was tired and she wouldn't stop crying has been jailed in Western Australia for a minimum of 12 years.
Arron Colin Martin, 37, had been tag-teaming care of six-month-old Isabella with his wife Nicole Martin, who was also a shift worker, for less than two months in November 2017 when he killed the infant.
Their only child died from catastrophic injuries he inflicted after returning to their Brookdale house from an early morning shift.
He told his Supreme Court of WA trial in March he "just snapped" because he was sleep-deprived and the baby, who showed signs of a cold and teething, wouldn't settle.
He hurled the infant from a height of almost two metres, saw her head start to swell and she was still breathing but he did not call for help.
Instead, he picked her up, put her in her cot and left the room.
He twice tried to end his own life at the house, sat in a park, then eventually turned himself in to police.
The mother only discovered what happened when she came home from work to find police officers and paramedics, who unsuccessfully tried to resuscitate the infant.
The court heard Isabella suffered skull fractures and hemorrhaging, and survived for up to five hours after the attack.
Martin told police he threw the baby to the ground but argued at trial he dropped her, explaining away his earlier comment as seeking to have "the book" thrown at him.
Justice Stephen Hall said the child's severe injuries required considerable force and he did not accept she had been merely dropped.
He said he was not satisfied Martin had formed the intention to kill Isabella but did intend to cause her bodily harm.
Martin had no history of violence, appeared to have been a good husband and father prior to the killing, and showed remorse immediately afterwards, but what he'd done was dreadful, the judge said.
"This is a terribly tragic case," Justice Hall said handing Martin a life sentence with a minimum of 12 years.
"You momentarily lost control. There was no planning, forethought."
He said the mother's victim impact statement showed her pain was still raw.
Ms Martin said her life was perfect when she left for work as a McDonald's manager that day, but it had been taken away hours later and she was robbed of the chance to say goodbye to her daughter.
She often thinks how different life would be if her husband had simply called and asked her to come home, Justice Hall said.
Martin fathered Isabella through artificial insemination as prescription drugs he'd been taking for anxiety and depression had ended his sexual relationship with his wife.
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