Ana Lucia Cortez is a former LAPD officer who was fired after she killed a man who had, in an earlier incident, shot her while she was pregnant and killed her unborn child. She went to Australia as the body guard of Christian Shephard, Jack's father, and was on her way back to L.A. after having decided her job there was done. She was a survivor from the tail section of the plane, which landed on a different part of the island, and was the leader of the group that would become known as the tailies. She is extremely distrustful of others and is not above using violence to protect herself and her fellow crash survivors.