A MOTHER who stabbed her three young children to death has been found dead in her room at a high-security hospital.
Theresa Riggi killed eight-year-old twins Austin and Luke and five-year-old Cecilia after fleeing from Aberdeenshire during a bitter custody battle with her estranged husband.
She stabbed the children eight times before causing a gas explosion at the Edinburgh flat where they were staying and trying to commit suicide.
The 50-year-old, previously of Skene, near Westhill, admitted killing the children and was jailed for 16 years.
Shortly after arriving at Cornton Vale Prison, near Stirling, she made a second failed suicide attempt and was later the alleged victim of a string of attacks.
Riggi was moved to a secure psychiatric hospital in Edinburgh, but last month it was revealed that she had been transferred to Rampton Hospital in Nottinghamshire.
Now, an investigation has been launched at the high-security facility after the US-born killer was found dead in a bedroom early yesterday.
A spokeswoman for the hospital said: “We can confirm there was a patient death at Rampton Hospital.
“We cannot reveal any other details because of patient confidentiality.
“Because it was an unexpected death, there is an ongoing investigation and we have informed the next of kin.”
A Nottinghamshire Police spokeswoman said: “We can confirm that we were called to Rampton in the early hours of Monday morning to the death of a woman.
“It’s not being treated as suspicious and we are preparing a file for the coroner.”
Austin, Luke and Cecilia were found lying side by side on a bedroom floor after their mother stabbed them on August 4, 2010.
After the killings, the devout Catholic flung herself from the balcony of the townhouse, but was revived.
Police charged her with the murders of the youngsters at her hospital bedside two days later.
She made her first appearance before a sheriff at Edinburgh Royal Infirmary.
Riggi made no plea and was committed to hospital under an assessment order – the type made when it appears an accused person may be suffering from a mental disorder.
Psychiatrists found she suffered from narcissistic, paranoid and histrionic personality issues.
The order was later revoked and, when her case called at the High Court in Edinburgh, she admitted three charges of culpable homicide on the grounds of diminished responsibility.
Jailing her for 16 years, Lord Bracadale told her she had taken her children’s lives with a “disturbing degree of violence”.
After Riggi was sentenced, her husband and the children’s father, Pasquale Riggi, said no jail term would provide justice for the “selfish, brutal and murderous acts” his wife had committed. “I will never forget Austin, Luke and Cecilia – they left everlasting impressions on me,” he said.
“I think about them at least 100 times each day. They are in my thoughts when I wake in the morning and before I go to sleep at night. They were such wonderful, energetic, bright and happy children.
“There is no justification for this heinous crime, repeated three times.”
Riggi began her sentence at the all-female Cornton Vale Prison, where she was allegedly thrown down stairs by one inmate and permanently disfigured by another, who allegedly slashed her with a razor blade.
After being transferred to a secure unit in Edinburgh, she was moved to Rampton Hospital as medics felt they would be better placed to treat her there.
Anyone contemplating suicide of self-harm can contact The Samaritans on 08457 909090 or Breathing Space on 0800 838587.