Britain's youngest double murderers Kim Edwards and Lucas Markham were just 14 when they slaughtered Liz Edwards, 49, and her daughter Katie, 13, as they slept in their beds. After knifing the mother and daughter ten times, the twisted young couple ate tea cakes and ice cream before watching the vampire movie series Twilight and having sex. The two had developed a morbid obsession with the murder of school pal Adam Free's dad Warren just months before the double killing. Written by Ulf Kjell Gür