Thou Shalt Not Kill

Episode 6 (1x6)

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Arianna Lancise finds her 4-year-old daughter dead in the car, where she had left her for just several minutes. The lack of clues leads the police and public opinion to blame Arianna, but Valeria is convinced that she is completely innocent. While Valeria attempts to prove the Ariana’s innocence, Monica confesses that Lucia, has always been innocent as well - she wasn't the one who killed her husband and Valeria's father, Mario. Who did?