Most people would find it difficult to fathom how a person could bash a baby to death.
The father of a man accused of carrying out such an act says he can't either.
Joude Khazma's 23-year-old son Mohammed was arrested on Monday and charged with bashing a two-year-old girl in the Guildford granny flat that he shared with the baby's mother.
"If my son has done this, he should face the full force of the law," Mr Khazma, 47, told Fairfax Media on Wednesday. "We don't condone this behaviour at all in the Khazma family or in our religion. This is not his upbringing, we are a humble family, we are not trouble-makers."
The father-of-six feared his son, a mechanic, had changed drastically due to drugs. He said he was heartbroken at the loss of the "sweet, friendly" young girl he had met a handful of times.
"Our heart bleeds for her family," he said. "If there's anything we can do to soften their grief and turmoil then we will do anything for them."
Mr Khazma and his family are struggling to understand the sequence of events that led up to the baby's mother driving into their front yard in McCredie Road, Guildford West, at 3.30pm on Monday.
His son Mohammed met the woman, who cannot be identified for legal reasons, six weeks ago through Facebook and they moved into the granny flat in Marian Street, Guildford, two weeks ago.
Joude Khazma was standing on his doorstep rolling a cigarette before leaving for a 12-hour shift as a security guard when the mother's silver sedan screamed into his yard.
She was yelling "Mohammed killed my baby!" he said. As Mr Khazma looked onto the car's back seat and saw the girl's limp body, he screamed "Oh my god" so loudly that several neighbours came out into the street.
He said he yelled at one neighbour to take her pulse as he dialled triple zero. The baby's mother collapsed on Mr Khazma's wife. Police arrived within minutes and Mohammed was arrested about an hour-and-a-half later in a Fairfield park.
Police allege he and the mother were present during the assault on Monday. At some point, he left the flat and the mother fled to his parents' home.
After the young girl succumbed to her injuries in hospital on Tuesday night, police said his charge would be upgraded to murder.
Mr Khazma's wife said she asked the mother why she had driven to their house – about four minutes from the granny flat – instead of going to a hospital or calling triple zero.
She said the mother told her she had called her aunt, who told her to go to the Khazma's.
The mother said the baby was injured about half an hour earlier. She said she couldn't leave the flat.
It's understood child welfare services had previously been involved with the child.
Mrs Khazma said the girl accidentally smashed a glass table at their home three weeks ago and cut her leg badly but the mother refused to take her to hospital.
She said she had noticed bite marks and bruising on the girl as well.
"I said to my husband, something's not right," she said. "I didn't know what to do. I wish I had done something."
Mr Khazma said he has not spoken to his son since his arrest and doesn't want to. The matter returns to court in January.