Alice Mackey, 42, had a “delusional” belief that the “best way to protect” her child Annabel “from a bad mother was to kill her”, said the judge Mr Justice Saini.
Mackey, who had previously pleaded guilty to manslaughter by reason of diminished responsibility, drowned the child 300 metres from the family home in Kingsley, Bordon, Hampshire, on 10 September 2023.
The girl was taken to hospital in a serious condition but died the following afternoon when the life support machine was switched off.
Prosecutor Adam Vaitilingam KC said: “The defendant had taken Annabel from their house to a nearby pond and held her under the water until she stopped struggling and Annabel died as a result.”
He added that Mackey had then phoned 999 and “lied” to police and doctors, saying somebody must have taken Annabel from the house, before claiming she had found her in the pond.
At Winchester Crown Court, the judge said she was under a “delusional” belief that “the best way to protect her (Annabel) from a bad mother was to kill her, you falsely believed she was not flourishing under your care and, in fact, was suffering under your care”.
Mr Justice Saini said: “You considered in your deluded state that this was some form of mercy for Annabel.”
The defendant had entered a not guilty plea to a charge of murder. The court heard this was acceptable to the prosecution.
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‘Unable to make rational judgement’
According to reports by two psychiatrists, she was suffering from a condition that meant she was “substantially impaired so unable to make a rational judgement” at the time of the incident.
Mackey had suffered postpartum (post natal) depression and anxiety following the birth of Annabel and had been prescribed anti-depressant and anti-psychotic medication, the court heard.
Mr Vaitilingam added that in May 2022, Mackey was sectioned to a mental health hospital for a month before she was discharged into community care.
Mackey, who worked at a school for children aged four and five where Annabel also attended a nursery, had stopped taking the anti-depressant medication in January 2023 and her mental health had deteriorated in the weeks before the fatal incident, the prosecutor said.
But she did not tell anyone and attended social events, including Goodwood Races, the day before she drowned Annabel, Mr Vaitilingam added.
‘Devastating effect on my life’
Annabel’s father, Peter Mackey, who works in IT sales, said in his victim impact statement to the court: “Her loss has had a devastating effect on every part of my life.
“I am deeply traumatised of the thought of how my daughter was killed, I am tormented by how frightened she must have been, at the pain she endured and the distress she suffered.”
Patrick Gibbs KC, defending Alice Mackey, said: “She is sorry for taking Annabel’s life, she is sorry for all the pain she has caused to anyone who knew and loved Annabel, she regrets every moment of what happened and she wishes above anything in the world that Annabel was still alive.”
