Ziva also bears the brunt of Gibbs' anger after Caitlin Todd was murdered. Ziva ultimately kills Ari, who was also her half brother, in order to save Gibbs' life.

Why did Ziva kill Ari?

Ari always believed that his father never realized Ari had turned against him. ... However, four years after Ari's death, NCIS Director Leon Vance revealed that Eli had actually become aware of Ari's treachery, and had ordered Ziva to kill him, both to dispose of a rogue Mossad agent and to earn Gibbs's trust.

Does Ziva kill Ari?

Just before Ari can kill Gibbs, Ziva who had been at the top of the stairs, listening to the two men talk, shoots Ari in the forehead, killing him instantly.