The teenager accused of murdering an elderly widow in north Wales was a vampire-obsessed youth who drank the blood of his victim during a "particularly gruesome killing", a court heard.

The 17-year-old, who cannot be named for legal reasons, denies murdering 90-year-old Mabel Leyshon in her home in Llanfairpwll, on Anglesey.

These are not the views of a mentally unstable defendant - he is perfectly sane and there is no medical issue whatsoever for you to consider.

Prosecutor Roger Thomas QC

Prosecuting, Roger Thomas QC told Mold Crown Court the heart of the victim had been removed, wrapped in newspaper and placed in a saucepan.

The body of Mrs Leyshon was found on Sunday, 25 November last year at her semi-detached bungalow.

She had died from multiple stab wounds and her chest had been "ripped open".

Pokers were left at her feet in the shape of a cross, the jury heard.

"Strong evidence"

Mr Thomas said DNA in blood found at the scene matched that of the defendant.

"This is extremely strong evidence," he said.

The chance of another person's DNA matching the sample was one in 73m, he added.

The defendant, from Anglesey, was arrested a month after a BBC Crimewatch UK reconstruction of her last known hours.

Forensic officers enter the murder scene

It was alleged that he had previously talked to a girl at a party about his desire to become a vampire and to be immortal.

He had told her the small village of Llanfairpwll was a "perfect place for vampires".

"The person who entered the house murdered Mrs Leyshon, removed her heart and drank her blood is this defendant," Mr Thomas said.

He added the murder had not been a sudden outburst of violence resulting in death - but a brutal and vicious murder that had been planned.

"Sacrifice"

"By 24 November, 2001, the defendant had learned quite a lot about vampires, certainly enough to satisfy his two main questions - how do I become a vampire and how do I become immortal?"

"He had decided what he had to do - a sacrifice, the murder of another human being was necessary to achieve his ends.

"And with his parents away he committed what we submit to you was a planned, deliberate murder to satisfy his own grotesque and selfish ends."

Mr Thomas said the defendant was not mentally unstable, and was responsible for his actions.

He told the court the circumstances of the murder were particularly gruesome, and that he would try to ensure the amount of disturbing material placed before the jury would be limited.

A rear patio door window had been broken and when two police officers entered the house and went into the TV room they were confronted by the body of Mrs Leyshon.

"It soon became clear that this was not simply the murder of a defenceless old lady who had confronted a burglar," said Mr Thomas.

The case continues.