A man who killed a grandmother because he believed she was possessed by the devil has been found not guilty on grounds of insanity.

Keith Solly throttled his partner of eight months, Yvonne Tapp, to death at their home in Lady's Gift Road, Southborough on December 5.

During his trial Maidstone Crown Court heard the 62-year-old then piled furniture on top of her, before making bizarre phone calls to emergency services.

In separate calls to police before the body was discovered, Solly - a former Sevenoaks bus driver - was said to have sung 'Oh my darling Clementine' to an operator.

When officers went to the couple’s home Solly was wearing women’s clothes. He opened a window and declared: “I am Gladys.”

Prosecutor Philipa McAtasney told a jury at Maidstone Crown Court that psychiatrists had concluded that the 62-year-old was suffering from such abnormality of the mind when he killed the 58-year-old grandmother that he was insane at the time.

Laura Reid-Dick, a former partner of Solly, told the court he would have random outbursts and "explode over nothing" during their eight-year relationship, but stressed he was never violent to her.

His trial, which began on June 24, ended today after a jury of 12 people returned a verdict of not guilty by reason of insanity.

Jurors were asked to decide whether Solly “did the acts” that caused Mrs Tapp’s death.

The court heard the pair met when they were both receiving care from the mental health service Priority House in Maidstone in December 2013.

They became friends and then started a relationship. Solly moved into Mrs Tapp’s ground floor flat in Lady’s Gift Road following his release from Priority House.

Miss McAtasney said Solly was acting strangely in the days before the alleged killing.

He hired a Morgan sports car and made a reservation for him and Mrs Tapp at a Gravesend hotel but then went missing and went alone to two hotels in Essex.

Solly, who sat in the dock flanked by two mental health nurses, said “Thank you” after being sentenced by the judge Mr Justice Spencer.

In a statement read to the court after sentencing Miss Tapp’s daughter, Jennifer, claimed her mother was badly let down by mental health services.

Today’s verdict means 62-year-old Solly will now be detained indefinitely at the Trevor Gibbens Unit at Maidstone Hospital under the Mental Health Act.

Prosecutor Philipa McAstasney QC said Jennifer, whose mother also suffered mental health problems, felt the system had failed her.

“I don’t think they should have been living together,” said the statement. “The Government promises care in the community but where is this care for my mum? Where are the safeguards to protect her?”

Miss McAtasney added: “She refers to how nothing she says or does will bring her mum back or mend the hurt this man has caused.

”She hopes her mum didn’t suffer very much. She finds it very hard to live with what has happened.