- Grandfather who killed baby grandson says he was 'stressed' at time of his death
- Wayne William Downing's case labelled 'sad and tragic' at WA Supreme Court
- Court heard 48-year-old shook baby to try and get him to sleep when woken up
- Post mortem found baby suffered extensive brain, eyes and spinal cord injuries
- Baby found unresponsive by meth addict mother, who used during pregnancy
A man who confessed to killing his baby grandson by shaking him for up to six seconds was 'extremely stressed and depressed' at the time, a court heard.
Wayne William Downing's 'sad and tragic' case was heard at Western Australia's Supreme Court on Tuesday, detailing the death of three-month-old Noah Jayde Downing.
The 48-year-old pleaded guilty to unlawfully killing the child on a Midland property, in Perth's north-west, in May 2016.
He has been in custody since his arrest in August.
The ABC reported Noah was in the full-time care of Downing prior to his death, which occurred due to 'a little shake' to get the baby to sleep.
Prosecutor Katrin Robinson told the court Downing was asleep on the couch when he was woken to Noah crying on the night of the incident.
'As soon as I put him down I realised what I'd done … I was just trying to go off to sleep and to get some sleep,' Downing told the court.
The court heard the child was found unresponsive by his mother five hours later.
It was not until three years later Downing admitted to the incident - making a full confession in an emotional interview with police.Noah was in the care of Downing full-time, along with his older sister, who had spent most of her life with him.
The children were Downing's responsibility due to their mother, his daughter, being a meth addict and using throughout her pregnancy, the court heard.
A post mortem examination found Noah suffered extensive brain, eyes and spinal cord injuries due to being shaken.
Downing's lawyer, Pete Collins, told the court his client was suffering extreme stress, anxiety and depression at the time of Noah's death.
Mr Collins said his client's 'stress levels went through the roof' and that he was 'lucky to get a few hours sleep a night' once Noah arrived.
Downing had to cover the costs of both children, and the court heard Noah had worn the same set of clothes for months.
In a letter to Justice Anthony Derrick, Downing said: 'My anxiety and depression overwhelmed me. No matter what I get I will have to pay for it forever … I will never get over it."
Downing is expected to be sentenced on Wednesday.
Downing was arrested in August and pleaded guilty to manslaughter at Stirling Gardens Magistrates Court in February.
He shared an emotional tribute to Noah on his Facebook in the wake of his death in 2016.
'My first grandson Noah Jayde Downing missed deeply and everyday xx,' he wrote next to a photo of the baby.
The court heard on Tuesday there was no doubt Downing loved his grandchildren.
'Having watched the video record of interview, there can be no doubt whatsoever he loved both of his grandchildren and did his best to care for them,' Ms Robinson said, the ABC reported.