It's unfathomable, inexcusable, sickening.
The act of killing an innocent child is something most of us cannot comprehend. But an average of 25 children are killed each year by a parent in Australia, with children under the age of one at the highest risk of victimisation.
On Sunday morning, 14-month-old Sanaya Sahib was found dead in Darebin Creek, in Melbourne's northeast. After days of unanswered questions surrounding the little girl's grim discovery, police charged her 22-year-old mother with the toddler's alleged murder.
Police allege Sofina Nikat confessed to the murder on Tuesday night, with Detective Senior Sergeant Stuart Bailey telling an out-of-court-sessions hearing that Ms Nikat had made a "full confession" over the death of her daughter.
The day after charges were laid, Ms Nikat did not appear in the Melbourne Magistrates Court amid concerns over her mental state.
"In most cases, there is a strong mental health issue, which is very sad but that's the reality," Dr Jack White, Forensic Psychologist, told news.com.au.
Defence counsel Michael McNamara confirmed that Ms Nikat was examined by a doctor and a psychiatric nurse on the morning of the hearing, and was excused from attending the court proceedings.
It is understood that medical experts were concerned about what kind of effect the court proceeding would pose on her.
"Usually the mother is experiencing severe mental health problems. In fact, I don't know any cases that don't have a mother with problems," Dr White said.
"Sadly mothers are the ones that are more common [to killing their children]. But with fathers, it can be a revenge response."
In 2009, Arthur Freeman threw his four-year-old daughter, Darcey, off Melbourne's Westgate Bridge, in front of her two younger brothers and shocked witnesses.
His "inexplicable" actions were met with grief, horror and anger across the country, and in 2011 he was sentenced to 32 years prison for murder.
During a 2015 inquest in to Darcey's death, it was revealed that doctors were warned Mr Freeman was violent, but did not report him to authorities. It was also made evident that the then 37-year-old was angry and upset about receiving reduced access to Darcey, after a long custody dispute.
"I saw [Darcey's mother] Peta Barnes on 13 April 2007 and she disclosed problems with her angry, irrational husband who shoves and pushes her and is often angry at the kids," one doctor's statement said.
The morning Mr Freeman threw Darcey off the bridge, the inquest heard that he had called a friend in tears about losing a custody battle.
Senior Sergeant Damian Jackson told the inquest, in July 2015, that Mr Freeman had never provided an account of what happened that morning.
In an interview with The Age, Dr Ben Buchanan, of the Victorian Counselling and Psychological Services said that when there is violence in the home, usually towards the spouse, it can drive some fathers to kill their own children.
"The best predictor of future behaviour is past behaviour," Dr Buchanan said
"Physical abuse towards the partner is absolutely a sign of a propensity to use physical force against the children."
Dr Buchanan also admitted that men who kill their children often see a part of their partner within the child.
"Our children represent our spouses, they've got that symbolic representation of the mother but they are more vulnerable," he said.
"In the cases I've seen, it's very rare for them to blame the children; the children are a proxy by which they're getting back at the mother."
And while neither cases are categorised as filicide, when the parent murders a child and follows with suicide, Sam van Meurs, a psychologist at Canberra Clinical and Forensic Psychology points out, said in an interview with Kidspot that a mother who kills her children and then herself can often have a different motivation than a father in the same situation.
"For example Donna Fitchett killed her two children in 2005 and left a note to her husband that said, 'I just couldn't abandon our beautiful boys'," Mr Van Meaurs said.
"In contrast, men are more likely to kill their children for revenge or to punish their partners or ex-partners."
According to the most recent World Health Organisation statistics, there are around 31,000 homicide deaths of children under the age of 15 in the world each year.
In Australia between 2009-10 and among children aged 0-14, there were 24 deaths due to homicide and the rate of homicide was highest among infants less than one year old.
Jack Levin, an American criminologist, told USA Today that mothers who murder tend to kill their newborns on impulse. "The day a child is born is the day a child is most likely to be killed by a parent," he said.
Dr Phillip Resnick, director of forensic psychiatry at Case Western and is a leading expert on parents who kill their children, agreed.
"Younger children are much more likely to be killed than teenagers," Dr Resnick said.
In an interview with TIME magazine, Dr Resnick spoke of the 40 to 60 cases he had worked on in the US that involved parents who killed their children.
In the US, the figures are staggering. About 250 to 300 children are murdered by their parents each year.
While each tragedy falls under vastly different circumstances, Dr Resnick said there are usually five characteristics in which parents kill their children.
"The first is "altruistic." The classic case is the mother who plans to take her own life and believes that the children are better off in heaven with her," Dr Resnick said.
"Number Two is the case in which the parent is acutely psychotic. The third type is fatal battering [the child does something to anger the parent and they react]. The fourth is [to get rid of] an unwanted baby, for example an infant born out of wedlock. The final category is spousal revenge, [in which a parent kills the children to hurt the partner], typically after infidelity," he said.
While admitting the method of preventing crimes that involve parents murdering their children is a "complicated" one, Dr Resnick said access to mental health institutes as well as awareness of depression is mandatory in understanding what drives adults to harm their offspring.
"If a woman is very depressed and she has young children and makes a suicide attempt, there is 1-in-20 chance [in America] that she will try to take the kid with her. Specific inquiries about thoughts of harm toward children should occur in any evaluation of a seriously depressed [mother]," he said.
Dr White agrees, saying Australia needs to address its mental health facilities, and increase support for unstable parents.
"In some ways our mental health system is struggling, and sadly a lot of people don't get the treatment they require," he said.
"In the area of mental health, and a mother is not coping, they need to be provided with more assistance."