A mother smothered her toddler daughter with a "Minnie Mouse" pillow while she was taking an afternoon nap on the couch in their family home after becoming "obsessed" and "overwhelmed" with the child's autism diagnosis, a jury has heard.
The Central Criminal Court trial also heard that the woman described to gardaí how she held the pillow over the child's face as she struggled and screamed.
Her daughter called out for her daddy and finally let out a sigh, she said.
A consultant forensic psychiatrist told the murder trial that the defendant was suffering with "recurrent depressive disorder" at the time and fullfils the criteria for a special verdict of not guilty by reason of insanity.
In the days prior to the killing the defendant had carried out internet searches on suicide and mothers killing their autistic children.
She had convinced herself that her child had a more severe form of autism when the diagnosis was at the milder end of the spectrum.
The woman, who cannot be named by order of the court, has gone on trial at the Central Criminal Court today, having pleaded not guilty by reason of insanity to the murder of the three-year-old child nearly two years ago.
Garda Declan Hartley agreed with prosecuting counsel Paul Murray SC that the toddler was assessed for autism in a child development centre in January 2018.
The therapist in the centre said the child scored at the borderline spectrum of autism and noted that her mother had a high level of knowledge regarding the condition.
Mr Murray read a statement from the woman's husband to the court in which he said that his wife had been googling autism and found a form of autism called Pathological Demand Avoidance (PDA).
"She immediately convinced herself that was what the child had," said the husband.
The woman's husband said the therapist had said their daughter was on the spectrum.
"She had not completed her assessment but at the very worse she had mild autism", said the husband.
The woman's husband said he left home that day and his child was watching cartoons and seemed quite happy.
The husband said he never blamed his wife for what happened to their child as he knew it had to be a psychiatric event that she was having and depression had caused it.
The woman's sister said in a statement which read to the court that the accused became totally obsessed with autism and was "always" on the internet researching it.
The defendant was not sleeping and becoming angry and stressed about the diagnosis in the weeks prior to the incident, she said.
Another sibling said she received a WhatsApp message at 6.58am on February 4, 2018 from the accused saying that she was "cracking up" and could not handle it.
In her garda interviews, the defendant described the weeks before the killing as a "living nightmare" and said she felt "desperate", "overwhelmed", "in a panic" and "totally alone" after her child was found to be on the threshold with autism.
The court heard the woman smothered her child with a "Minnie Mouse" pillow while she was taking an afternoon nap on the couch in their family home.
She did not want her husband or her other child to be in the house at the time.
The child had been asleep on the couch for an hour and a half and the woman told gardaí she held the pillow over the child's face as she struggled and screamed. Her daughter called out for her daddy and finally let out a sigh, she said.
The woman said she intended her daughter to die.
Following this, the woman rang 999 and told them she had tried to suffocate her child. The woman did chest compressions on her daughter but said she looked grey.
"I was thinking why am I doing chest compressions when I put a pillow over her head," she told gardaí.
She had thought about going to the beach and drowning herself and had googled the words "toddler suffocate pillow", "drowning", "mothers killing autistic children" and "sentence for murder" on her phone in the days leading up to the killing.
'I did love her very much'
The accused told gardaí that she felt she did not have a choice but to complete the act in order for her other child to have a happy life.
"I wasn't in the best place, I did love her very much. I just wanted the best for her and to be as happy as possible. It was all go go go, I had to do it," she told gardaí.
"Asked if she had something to say to her child she replied: "I would say I'm so so sorry".
In cross-examination, Gda Hartley agreed with defence counsel Patrick Gageby SC that the woman was a very good mother to her children and put them first.
Dr Sally Linehan, a consultant psychiatrist from the Central Mental Hospital, gave evidence that the woman first experienced mental health frailties when she was in college and people had expressed concern about this.
When her daughter was diagnosed with autism she said she felt like it was the end of the world and could not accept that she had a mild diagnosis.
She latched onto PDA and found it terrifying and the woman said she was "googling way too much", noted Dr Linehan.
The accused's husband was more positive about the future but the accused could not see it. The woman's husband said in the weeks prior to the event she started texting everybody and saying the situation was catastrophic, explained the witness.
Dr Linehan said the woman suffers from a "recurrent depressive disorder" which is a mental disorder and it had an element of psychosis at the time.
The woman had been experiencing depressive symptoms in the months leading up to the killing and experienced a "morbid preoccupation" with the issue of her child's diagnosis as well as irrational thoughts that can reinforce negative and catastrophic thinking.
The woman's mental health deteriorated when her child's autism was diagnosed and she developed a conviction that she must kill her, said the witness.
She was experiencing a relapse of her depressive illness and was suffering from a mental disorder at time of the offence, she said.
The woman did not know what she was doing was wrong and was unable to refrain from committing the act, she continued, adding that she was satisfied that the accused fulfills the criteria of not guilty by reason of insanity.
In cross-examination, Dr Linehan agreed with Mr Gageby that his client had misinterpreted the severity of the child's illness.
The trial continues tomorrow.