Doctored evidence

After a wealthy elderly woman is found brutally murdered in her Venetian apartment, the police suspect her maid, who has disappeared and is heading for her native Romania. But when it becomes clear the maid could not have had time to kill the old woman before catching her train, Guido Brunetti decides-unofficially-to take on the case himself. As his wife reads about the seven deadly sins, Brunetti realizes that this is probably not a crime motivated by greed-rather, the motive may have more to do with the temptations of lust. But perhaps Brunetti is following a false trail and thinking of the wrong sin altogether...