A 13-year-old girl has been accused of murdering 43-year-old Marta Bednarczyk in a premeditated stabbing, leaving the victim with more than 140 wounds, a jury at Lincoln Crown Court heard. The court was told the teenager researched the killing online in the weeks leading up to the attack and sent messages to friends indicating she “probably wouldn’t be in school for a while,” suggesting she believed she could evade detection.
Prosecutor Samuel Skinner said the girl used multiple knives, inflicting at least 143 sharp-force injuries, including 65 to the head and neck, seven to the front of the torso, 33 to the back, and 18 to the hands and wrists. Some wounds penetrated Marta’s brain and lungs, with one requiring significant force to inflict.
The victim was found dead at her Wellingborough, Northamptonshire, home after a fire, having likely already died from her injuries. The defendant initially claimed a third party had attacked Marta but now admits to unlawful killing, claiming diminished responsibility. The prosecution disputes this, arguing her actions were premeditated and not caused by mental health issues, and that she should be convicted of murder rather than manslaughter.
The teenager, who cannot be named due to her age, attended the hearing accompanied by a social worker and intermediary. The trial is ongoing.

