A millionaire's teenage daughter who wrote a murder manual before killing an elderly woman has been jailed for life.
DNA from Adeyoola was found on Mrs Mendel
Kemi Adeyoola was 17 when she stabbed 84-year-old Anne Mendel 14 times during a burglary in March 2005 at her home in Golders Green, north-west London.
"You are a remorseless and cold-blooded killer who is a danger to the public," said Judge Richard Hone.
Setting a minimum sentence of 20 years in jail, the judge said Adeyoola might have gone on to kill again.
Judge Hone said: "I think you actually wanted to experience what it felt like to kill someone in cold blood, possibly so you could write about it, but more probably so you could boast about it and possibly even do it again."
The judge said he had had the opportunity to observe Adeyoola's "performance" during the trial.
"You are intelligent, manipulative and skilled in deceit way beyond your years," he told her.
The Old Bailey heard Adeyoola hatched a blueprint on how she would kill an elderly victim after robbing them.
Mrs Mendel, who was a former neighbour of Adeyoola, was found by her husband covered in coats in the hallway of their home.
Leonard Mendel, 81, told the court he tried to give his wife of 50 years the kiss of life when he returned from an errand to find the hall phone wires cut and blood on the walls.
The prosecution said Adeyoola had chosen Mrs Mendel as a "soft target" on which to practise before finding a "rich, elderly and defenceless" woman to kill for her money.
Anne Mendel's body was found by her husband
Adeyoola, now 18, had written plans for the killing while serving a sentence for shoplifting. Her aim was to make £3m.
But she claimed that the 18-page neatly-written murder manual found in a cell search at Bullwood Hall, Essex, was the draft of a crime thriller.
Adeyoola, who disposed of her bloody clothing, might have got away with murder but for a tiny speck of DNA found on Mrs Mendel's hand.
Henry Blaxland QC, defending, said: "The court has before it somebody who is, on the face of it, emotionally damaged.
"She finds herself utterly alone in the world given that her family have entirely washed their hands of her."
The teenager's father, Bola Adeyoola, who runs a property management company, said: "What she did was evil."