Playing with narrative voices is always a good idea, especially in literature, especially in crime literature. Flynn is particularly good at it, as she demonstrated in 'Gone Girl'.
This rather classic thriller delves into a cold case - nearly a whole family assassinated in their home, the story obviously told by the sole survivor in present time, and of her family members in flashbacks.
It was an OK pageturner, not much more. Definitely not up to the 'Gone Girl' standard.