A woman who killed her mother by giving her an overdose of insulin and smothering her with a pillow has been sentenced.

Shirley D'Silva, 55, of Morland Road in Croydon, was sentenced to an indefinite hospital order under the Mental Health Act at the Old Bailey today (Tuesday, July 18).

D'Silva pleaded guilty at the same court yesterday, (July 17), to manslaughter on the grounds of diminished responsibility.

On October 25 last year, at about 4.10pm, D'Silva dialled 999 and told the operator that she had just killed her 77-year-old mother Martha Pereira at the home they shared.

When the operator asked what happened, she replied: "Erm, nothing happened. I just decided to take her life."

When the operator asked D'Silva "what made you do this today?" she replied: ''It's the world we live around. We've been suffering too long. Nobody's doing nothing about it. Somebody has to come forward and do something about it."

D'Silva told the operator her mother had been unwell for a long time.

Later on in the call when asked by the operator "did you do it because you don't think you were getting the help you needed?" she replied: "No, no. It's not, it's not that. It's about the world, the war around the world going on.'

D'Silva remained on the phone until officers arrived at the scene.

She remained calm at first and when asked what happened, D'Silva told officers: "I have just killed my mother. I have given her an overdose of insulin and I have suffocated her with a pillow."

Officers and paramedics from the London Ambulance Service carried out CPR on Mrs Pereira but she was pronounced dead a short time later at a south London hospital.

A post-mortem examination showed the cause of death was consistent with an insulin overdose and smothering.

D'Silva was arrested on suspicion of murder at 16:18hrs on 25 October. She was charged on October 27.

When interviewed by officers D'Silva told them a man had told her to kill her mother, and he was now telling her to kill her husband and son.

Detective Sergeant Brendan Ward, the investigating officer from the Met's Homicide and Major Crime Command, said: "This is a very sad case and our thoughts and sympathies are with the family at this difficult time."