A deranged killer who stabbed a complete stranger to death in a supermarket car park has been sent to a secure mental hospital.

Kevin Gale attacked victim Lee Turner at the Tesco Express store in Barnstaple with a Spider-Man throwing knife which he used to stab him four times in the back.

Mr Turner did not know his killer and never even saw his attacker. His dying words were 'Why me? What have I done?'

Gale, aged 51, suffered from paranoid schizophrenia but had broken off contact with the mental health services after his key worker had left their job 18 months before.

He stopped taking strong anti-psychotic medication and attempts by his sister and daughter to alert the mental health crisis team to his deteriorating condition failed.

He built up a deadly collection of weapons including three Spider-Man knives, a samurai sword, and a gothic dagger.

He changed his name to Mr Kitkat and began dressing in strange clothing, including the glam rock-style silver wedge heeled boots and blue bandana he wore on the day of the killing on August 3 last year.

New father Mr Turner, aged 39, went to Tesco to buy two bottles of milk and the trigger for the attack may have been a 'strange look' he gave when he passed Gale, who was entering the shop as he left.

CCTV showed Gale stopping in the foyer, taking the weapon from his rucksack, and then turning back and pursuing Mr Turner across the car park before stabbing him.

Gale, of Rackfield Court, Barnstaple, was deemed unfit to plead but a jury at Exeter Crown Court found he had carried out the killing.

Judge Peter Johnson imposed an indefinite Hospital Order with a restriction that means Gale will be treated at Langdon Hospital, Dawlish.

He will not be released unless the Ministry of Justice and a Mental Health Tribunal conclude it is safe to do so. He was not present at either the trial or the sentencing hearing.

The judge said: "On any view, this is a particularly tragic case involving the death of a wholly innocent man at the hands of a stranger."

He concluded Gale was suffering from paranoid schizophrenia at the time of the killing which diminished his responsibility for his actions.

The judge expressed his condolences to Mr Turner's family and praised them for their dignity during the trial last week.

Mr Turner's brother, Clyne Hamilton-Daniels, called on the NHS's mental health services to be improved after the jury's decision last week.

The Devon Partnership NHS Trust, which runs the mental health service in Barnstaple, have announced an inquiry into the case, which will be led by an independent expert.