Katie Jenkin was a popular media studies student. She and her mother were killed by her brother John Jenkin at their home in Millom.
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Lee Clayton was caught as he tried to deal class A substances to an undercover security officer at the music festival in July last year.
Timeline: The death of four children was the culmination of a series of tit-for-tat attacks during a "petty" feud over three weeks.
Demi Pearson, 15, her brother Brandon, aged eight, seven-year-old sister Lacie, and sister Lia, three, all died.