@aryas1988 In the Uchiha massacre arc Danzo ordered Itachi to kill his clan. When Hiruzen Sarutobi found out about it he decided to take responsibility for it as well. Lord Third Hokages wanted to make peace with the Uchiha clan. Itachi was a double agent. I hope this answers your question. As for Shiori, she knows the truth behind the massacre but respects her older brothers' decision and doesn’t tell anyone else. The people who know the truth are Kena, Kane, Tori, Haruna, Hana, and Natsume.