A paranoid schizophrenic with a history of violence killed his grandmother after he reduced his medication because it made him feel too drowsy in the morning, a court heard.

When Stuart Lay told his mental health team about the reduced medication, they agreed he could stay on the lower dose.

But three months later he battered Jean Robertson, 86, to death at her Sittingbourne home because of delusions about "the ladder of life" involving the old being sacrificed to make way for the new generation.

The 44-year-old bricklayer was in October 1997 detained indefinitely under the Mental Health Act after he attacked his other grandmother, Miriam Lay.

He had kicked down the door of the 82-year-old’s flat in June that year and beat her with her walking stick and punched her. She never recovered.

He later told his mother he had intended to kill her.

Now, he has again been detained indefinitely under a hospital order.

Maidstone Crown Court heard by April 2014, Lay was “absolutely discharged” by a mental health review tribunal, having been out of hospital since 2000.

Prosecutor Philip Bennetts QC said Lay unfortunately decided to half his anti-psychotic medication in August last year because he was experiencing too much sedation in the mornings affecting his ability to work.

"As a result of the reduction his mental state finally relapsed fairly rapidly in the days and weeks prior to the killing," said Mr Bennetts.

"He felt under increasing stress both at work and in his relationship and he was drinking alcohol more heavily than usual, but he denies taking drugs.

"He may have missed his dose of clozapine altogether the evening before the killing."

"I have hit nan. I think I hit her with the chair twice and possibly once with the phone" - Stuart Lay, to his parents

On the morning of November 19 last year Lay, who had been a paranoid schizophrenic for over 20 years, asked his father Phillip about storing some of his possessions.

His father suggested he went to see his grandmother. He then went to Mrs Robertson's home in Rectory Road. Shortly afterwards he called his father and said he had done something.

His father and mother Carole went to the address. Lay told them: "I have hit nan. I think I hit her with the chair twice and possibly once with the phone."

Paramedics and doctors attended but Mrs Robertson was pronounced dead at the scene. The cause of death was multiple injuries.

Lay, of Homewood Avenue, Sittingbourne, denied murder but admitted manslaughter by reason of diminished responsibility.

Judge Jeremy Carey said Lay, who was sentenced by video link with Broadmoor Hospital in Crowthorne, Berkshire, had reduced his medication "with disastrous consequences".

Psychiatrists found he was suffering from "abnormality of mental functioning" caused by paranoid schizophrenia.

It substantially impaired his ability to form rational judgement and exercise control.

The judge said of the hospital order: "Those who are not lawyers cannot necessarily either understand or have any sympathy with such a direction - and why should they when there is a death by killing.

"For those who love, respect and mourn such a person it is entirely understandable they wish there to be a recognised form of sentence. They should not be thought less of.

"But this court has to sentence in accordance with the law and in accordance with the evidence of the compelling nature of the recommendation made by psychiatrists."

"At the age of 86 her life was in an untimely and appalling way brought to an end. I must have in mind protection of the public" - Judge Jeremy Carey

After Lay was sentenced to an indefinite hospital order under the Mental Health Act, he asked: "Can I say something please?"

Judge Carey replied: "No, thank you."

Mark Dacey, defending, said Lay's parents had been supportive of him, but not all family members shared that view.

"It is a tragic case," he said. "When there was a reduction in medication his parents felt they were not informed as an at risk group."

Judge Carey said he would not "raise the temperature of the case" but commented it was understandable that some family members were not supportive of Lay.

"Why should they be?" he said. "This is a terrible incident which must have had a devastating impact even on those doing their best to support the defendant.

"Those who do not support him are entitled and will have recognition of that fact. I haven’t hear anything about this lady but proceed on the basis she was a thoroughly loving and good mother and grandmother.

"At the age of 86 her life was in an untimely and appalling way brought to an end. I must have in mind protection of the public.

"It was an appalling incident for this family, not for the first time."

After today's sentencing hearing, Detective Inspector Ivan Beasley, of the Kent and Essex Serious Crime Directorate, said: "This was an unprovoked incident where a 44-year-old man overpowered his victim, causing fatal injuries.

"What may have started as a routine visit to his grandmother, ended in her death when Lay’s behaviour changed.

"This is a tragic loss for a family and Lay is now in a secure unit where the public can be protected and he can receive the medical treatment he needs."