As the jury returned a unanimous verdict, the 17-year-old wept in the dock and his mother shrieked and sobbed in the public gallery.

Mabel Leyshon was stabbed to death at her home in Llanfairpwll on Anglesey, in November 2001.

Hardman - who had lived just a few yards away and had been Mrs Leyshon's paper boy - mutilated her body before placing pokers at her feet in the shape of a cross.

Her heart had been removed, wrapped in newspaper and placed in a saucepan on a silver platter next to her body.

The prosecution said her killer drank her blood in a "macabre ritual".

After the verdict was delivered, the judge lifted a ban on naming Hardman which had been in place throughout the trial.

The prosecution said the teenager - who denied the charge - was obsessed with vampires and the occult, and had told others he wanted to kill someone in order to become immortal.

The 14-day hearing was told how he smashed his way into Mrs Leyshon's bungalow where he was watching television.

He stabbed her 22 times. DNA found at the murder scene matched that of blood found on a knife at Hardman's home.

The court was told of an incident two months before Mrs Leyshon's murder, when Hardman had accused a 16-year-old German girl of being a vampire.

Claiming she was "one of them", he begged the student to bite his neck so that he too could become a vampire.

When she refused, he became violent and began insisting, pressing his neck against her mouth. Eventually the girl had to summon help.

The prosecution also outlined how Hardman had surfed the internet for vampire websites and had read a magazine which featured an article on how to conduct a black mass.

The teenager denied being "obsessed", and told that court that his alleged fascination with vampires was nothing more than a "subtle interest".

Sentencing Hardman, Mr Justice Richards ordered that he be detained at Her Majesty's pleasure - a life sentence - and ruled that he should serve a minimum of 12 years for the murder.

"It was planned and carefully calculated," he said.

'Brutality'

"Why you, an otherwise pleasant and otherwise well regarded young man, should act in this way is difficult to comprehend.

"You had hoped for immortality. All you achieved was to brutally end another person's life and the bringing of a life sentence upon yourself."

A jury took almost four hours to reach a verdict at the end of a trial which had been so gruesome journalists had found it difficult to report.

Hardman had been living with his mother Julia, a nurse, and her partner Alan Benneyworth, a former Ministry of Defence fireman, in a bungalow in Llanfairpwll.

Asthma attack

Born and raised in Amlwch, on the north coast of Anglesey, he moved to Llanfairpwll in 1998, when he was 13 years old.

That same year, his father - who had been separated from his mother - died from a massive asthma attack.

Although his parents lived apart, Hardman had remained close to his father and was upset by the tragedy.