AN NHS investigation has been launched following the killing of a woman by her son.

A judge said the frenzied attack on Mary Annie Sowerby, 69, by her son, Lee, 45, could have been prevented with proper mental health supervision.

The Honorary Recorder of Preston Judge Mark Brown said he had serious concerns about the way Sowerby’s case had been handled since the 1990s and called for an inquiry.

He said: “Something needs to be done if only to ensure that lessons are learned and these type of dreadful situations do not happen again.”

However the Cumbria Partnership NHS Foundation Trust said an inquiry had already been launched following the tragic death and it is “already implementing lessons learned”.

In a statement the trust said: “Our thoughts and sincere sympathies are with the family and friends of Mrs Sowerby at this extremely difficult and distressing time.

“Following the tragic death of Mrs Sowerby we launched an internal investigation, which is still ongoing, and we were fully co-operative with the police investigation.

“Once concluded, findings will be shared with the family and the coroner.

“We are committed to providing the best possible service that we can for our patients and have already started to implement learning from this tragic event and will continue to do so across mental health services.”

Mrs Sowerby was attacked by her son in her Dearham home on January 22. He had been due a medication review the day before the attack but this had not taken place.

Sowerby, of Honister Drive, Workington, admitted manslaughter on the grounds of diminished responsibility.

He was sentenced to life with a minimum of 11 years.

Preston Crown Court heard Sowerby started suffering from drug induced psychosis in the 1990s after getting involved with the rave scene.

In 1996 he carried out an armed robbery and bomb hoax at a bank and was handed a hospital order under the mental health act.

In 2008 he tried to stab his brother’s girlfriend and was only stopped when his brother rugby tackled him to the floor.

Judge Brown said: “Despite the seriousness of that charge and your violent background you were only detained in a secure hospital for 18 months and in 2012 you were granted an absolute discharge.”

Following his release, Sowerby’s mental health continued to deteriorate as he refused to comply with his medication regime and continued to abuse drugs and alcohol.

In March 2018 he was admitted to hospital after being found carrying three knives and displaying paranoid ideation.

In October 2018 an alert was put on Sowerby’s file after a mental health worker visited him at home and saw a knife on display in the living room, which Sowerby said was to protect him against drug dealers.

In January 2019 he attended Workington Police Station wanting to confess to murder in a previous life, believing he was Adolf Hitler. He was seen by two police officers but no action was taken.

In the early hours of Tuesday January 15, two police officers saw him walking along a fast country lane with his dog. They stopped and spoke to him and he told them he was struggling with his mental health and had set off on the seven-mile walk to see his parents. The officers gave him a lift to his parents’ home but again did not call an ambulance taken as he appeared articulate, and on the face of it rational, the court heard.

On January 16, Sowerby attended at Park Lane Community Mental Health facility with his father, asking to be put back on medication. In a victim statement, Mr Sowerby said he believes if his son had been seen by a doctor he would have been sectioned immediately. Sowerby returned to his parents’ house and a medication review was arranged.

On January 22, Sowerby killed his mother.

Judge Brown said: “The very many injuries demonstrate this was a brutal and frenzied attack in which a vulnerable woman lost her life in the most appalling circumstances.”

He said: “Had the restrictions order not been discharged absolutely in 2012 I very much doubt this killing would have happened. He would have been recalled to hospital far, far sooner, and been detained in hospital.”

In victim statements, Mrs Sowerby’s husband Leonard and son Daniel said the killing had devastated the family.

More than 400 people attended Mrs Sowerby’s funeral.

Daniel sat in court throughout the sentencing, but his father was too upset to watch the proceedings.