Portrayed by Jessica Steen, she first appeared in the episode Minimum Security . Paula Cassidy was a criminal profiler for the Naval Criminal Investigative Service. An expert on Middle Eastern terrorists, she worked as an interrogator at Guantanamo Bay. After her team was killed, she sacrificed herself to stop a suicide bomber in the episode Grace Period , thus saving Gibbs, DiNozzo, Ziva, and three Muslim clerics, who were signing fatws to promote peace in the Middle East.