Complex sentence: Frost remembers that he and Lynch came up with the notion of the girl next door leading a "desperate double life" that would end in murder, which was inspired by the unsolved 1908 murder of Hazel Irene Drew in update New York.
Split into simpler sentences: Frost remembers that he and Lynch came up with the notion of the girl next door leading a "desperate double life" that would end in murder. The idea was inspired, in part, by the unsolved 1908 murder of Hazel Irene Drew in update New York.