Caitlin Todd (Sasha Alexander)

Caitlin "Kate" Todd was a former Secret Service Agent who was originally assigned to the USS Presidential Protective Detail on board Air Force One and as such, had the code-name, "Rosefern". However, following the events of Yankee White (episode), she resigned from the Secret Service and joined NCIS before being assigned as Junior Agent to the Major Case Response Team, becoming the third member of the team and Anthony DiNozzo's second partner.

However, her year and a half-long career as an NCIS Special Agent which had the promise of great things came to an abrupt and very tragic end when in the last few seconds in the Season 2 finale, Twilight (episode) in a truly shocking move, one that the team's enemy, Ari Haswari had arranged, Kate, having originally taken a bullet for Gibbs died seconds later after being shot in the head, leaving her NCIS colleagues devastated and grief-stricken over her death. Kate's position on the team which was left vacant after her murder was later taken over by Ari's control officer and half-sister, Ziva David who joined the team as the NCIS/Mossad Liaison Officer and later became an NCIS Special Agent while Kate's former psychological profiling abilities were taken over by Donald Mallard.