A Dorset teenager who murdered his mother after becoming fascinated with knives has been sentenced to life imprisonment.
Kieren Smith, 17, stabbed 42-year-old Leah Whittle 94 times at her home in Benville Road, Weymouth, on July 21, following a "two-year diet of constant DVDs".
Sentencing Smith at Winchester Crown Court, Judge Guy Boney told him he had "not shown a smidgen of remorse" and would serve at least 15 years before he could be considered for parole.
The eight-day trial heard Smith attacked his mother in the flat they shared before he lied to police, saying she had been killed by drug-dealers.
Smith was expelled from school at the age of 14 and had spent the last two years alone in his room, watching DVDs, the court was told.
Nicholas Haggan QC, defending, said the teenager's motive for the killing was unknown. He added that Smith, who has an IQ of 72 – putting him in the lowest 4% of the population – had been excluded from school after becoming disruptive, leading to drink and drugs problems.
Mr Haggan told the court the defendant had become isolated and shunned contact with others to avoid getting emotionally hurt, saying: "For the two years prior to the killing, the defendant spent it alone in his room watching DVDs. He led a very lonely existence."
Richard Smith QC, prosecuting, said that Smith, who was 16 at the time, had an interest in knives and had a temper, but said the reason for the murder would never be known.
The youth denied the killing and said men came down from Doncaster to execute his mother because his brother had got into trouble over a drug debt.
Ms Whittle had moved back to Dorset after living in Yorkshire until her marriage broke down.