A 13-year-old girl accused of murdering a woman in a pre-planned stabbing inflicted more than 140 wounds on the victim, a jury has heard. Jurors were told the teenager had conducted online research before the killing, and 43-year-old Marta Bednarczyk was probably dead before her body was burned in a fire at a terrace property in Wellingborough, Northamptonshire, in March.
