The girl with the little dog

A girl is found stabbed dead; she was staying in a Roman hotel. Rocca investigates her past and discovers that she had been kidnapped when she was ten years old: her parents, left broke following her payment, kill themselves. It is the kidnapper (owner of the hotel), whom the girl had recognized from a tattoo and who was following in her footsteps, who killed her. Francesca will figure out who it is from her tattoo and be saved by Rocca when the innkeeper tries to kill her.