Thou Shalt Not Kill - Season 2 Episode 18
Overview: Marta Valente is bound and gagged while the corpse of her son Christian, a boy with severe mental retardation, and of Luigi Merlo, director of the hippotherapy center for the disabled who treated the young man, lie a few meters away. The first hypothesis formulated by Inspector Valeria Ferro is that of a robbery but the presence of an "inconvenient" witness reveals much more.