A schoolgirl who stabbed a woman 143 times researched what the sentence would be if she was convicted of murder, a prosecutor told a court today.
Marta Bednarczyk, 43, was found in a smoke-filled living room in her burnt-out home in Wellingborough, Northamptonshire in March where she was declared dead at the scene.
Although her body was found burnt in a fire, a post-mortem examination found Marta had suffered injuries to her neck and back, likely killing her before the fire.
A pathologist found she had suffered at least 143 sharp force injuries, including 65 in her head and neck with suggestions that more than one knife was used.
Marta had seven wounds in the front of her torso, 33 in her back, ten in her arms and 18 on her hands and wrists.
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One of the knife wounds had gone through the brain, which jurors heard would have needed ‘severe’ force to do so.
Jurors at Lincoln Crown Court heard that the alleged teen killer initially claimed a third party had attacked the mum-of-three.
But when the girl was taken to hospital, a police officer and a nurse allegedly saw her smiling.
Prosecutor Samuel Skinner KC said the killing had been planned for several weeks before and she messaged her friends saying she ‘probably wouldn’t be in school for a while.’
Mr Skinner added: ‘She also researched what the sentence would be for a 13-year-old convicted of murder.
‘Whatever she might say now, we say that this killing was premeditated.’
A motive for the murder may never be known, prosecution has said.
The girl has admitted unlawfully killing Marta but denies murder by using the diminished responsibility defence.
Mr Skinner said: ‘In truth this issue of diminished responsibility is likely to be the main focus of your attention in this trial because we, the prosecution, do not accept that she has the benefit of the defence of diminished responsibility.
‘We say that we will make you sure that this is a case of murder because she intended to do really serious harm.
‘We say it is murder because she planned the killing, and we say it is murder because she lied about what she did.
‘And we say it is murder because there are genuine specialists in this field of psychiatry and psychology that say her actions were not caused by poor mental health.’
Because of the girl’s young age, she is sat on the back row of the court benches accompanied by an intermediary and her social worker.
Also, the judge and barristers in the case are not wearing gowns or wigs, and jurors have been told the sitting hours will mirror those of a school day.
Marta moved from Poland to the UK in 2010 – first to London and then to Wellingborough in 2012, where she worked hard in a warehouse to provide for her family.
In an earlier tribute to Marta, her family praised the mother-of-three as ‘the matriarch of our family.’
They said: ‘She was a very caring woman, a loving mother, and a supportive friend who could never do enough for those she loved.
‘She was so loved by all of us and the tragic circumstances in which she died will haunt us forever. We don’t think we will ever come to terms with it.
‘We are heartbroken at the thought of never seeing our lovely Marta again. She will be missed beyond words, and she will never be forgotten.’
The trial is expected to last for up to three weeks.
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