A South African mother who admitted suffocating her three young disabled children in London suffered from an "abnormality of mind", the Old Bailey heard on Monday.
Prosecutor Zoe Johnson, QC, told the London court Tania Clarence, 42, had a "major depressive episode" at the time of the killings, the UK-based Press Association reported.
To Clarence, the quality of her children's lives was more important than their longevity -- which was "entirely understandable", Johnson said.
"It is clear on the evidence Mrs Clarence killed her three children because she wanted to end their suffering and at the time she committed the act she could not see any alternative or any other way out of their joint suffering," she said.
Clarence's lawyer Jim Sturman, QC called for her to be handed a hospital order.
He said his client manifested stress throughout the life of the children by their suffering.
Caring for them with this condition was exhausting, distressing, and debilitating, and turned out to be overwhelming, he said.
Overdose of pills
She had "no hope for the future" and her suicide attempt was genuine, said Sturman.
Clarence reportedly took an overdose of pills and slashed her wrists after suffocating her children, twin boys who were three years old and her four-year-old daughter in April.
The children had type two spinal muscular atrophy, a condition which affects muscle strength. The condition caused a person to be unable to stand unaided. It also caused difficulty with movements and led to a vulnerability to respiratory infections.
The court heard that Clarence wrote three notes after killing her children. One of them was written to her husband, Gary.
"Gary, I don't want to be saved please. I can't live with the horror of what I have done. I thought the pills would work, they didn't," she reportedly wrote in Afrikaans.
At the time of the killing, her husband was in South Africa and was not due to return home for a few more days.
A nanny and a neighbour who were worried about Clarence had gone to the house and found the injured mother and dead children.
Clarence has pleaded guilty to manslaughter but denied murder.
The court on Monday accepted her plea, meaning she would no longer go on trial as scheduled next year.
She would be sentenced on November 14.
Clarence was not in court on Monday, but her husband Gary attended.
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