Paula Cassidy was an NCIS Special Agent who was originally assigned to Guantanamo Bay as an interrogator.
She later returned to Washington D.C. before being reassigned to the Pentagon where she led her own team before she died in the line of duty in April 2007.
Not much is known about Cassidy's history but according to her file, she was born in an unnamed area of Canada.
She later emigrated to the United States, presumably gaining citizenship and ultimately joining NCIS.
As an NCIS Agent she worked at Guantanamo Bay interrogating and terrorists. At Guantanamo Bay she befriends Nasseer Al Jazair, a convicted terrorist and worked hand in hand with him. The two had a mutual relationship. He helped her by giving her info and she helped him by giving him better accommodations in the prison.
NCIS Season 1Edit
We first meet Agent Cassidy in Season 1 Episode 8 "Minimum Security" when Gibbs, Kate, and Tony follow a lead that takes then to Guantanamo Bay. At first Gibbs suspects that Agent Cassidy may be involved in his investigation but her story later clears out. She helps Gibbs and his team take down Nasseer Al Jazair before he is able to finish his mission in assassinating another inmate. In addition she also begins a flirty yet harmless relationship with Very Special Agent Tony Dinozzo
NCIS Season 2Edit
Sometime following the events Guantanamo Bay in season 1 Agent Cassidy gets transferred to be Agent Afloat aboard the USS Kennedy. When Tony is sent aboard the USS Kennedy to follow up on a lead he comes into contact with Agent Cassidy yet again. There is an awkward tension between the two of them dating back to there short fling a year ago in Guantanamo Bay. Cassidy assists and helps Gibbs and her team
Later in the season Dinozzo mentions that Cassidy's ship is coming to town and that the two are hooking up later. This never happens how later in the episode Kate Todd dies.
NCIS Season 3Edit
With Kate Todd dead, Gibbs team needs a fourth team member so Cassidy stay to help out. The team has to investigates a serial killer named Kyle Boone that was caught some time ago by Gibbs. Boone was killer who was responsible for the death of many young girls. Boone is on death row and claims that he will tell Gibbs where the 'other bodies are'. During the investigation it is clear that there is another killer who is either a copycat or an accomplice. When Cassidy, Dinozzo, and McGee go to investigate the new killers dumping ground, agent Cassidy is violently abducted. She is taken to Boone's barn where the new killer attempts to kill her. Somehow either Gibbs rescues her or she fights him off but the next shot we see of her is in the NCIS building with a cast on her arm and a couple of cuts and bruises. After Ziva joins the team agent Cassidy is given her own team.
NCIS Season 4Edit
Cassidy and her team are sent to investigate a potential terrorist tip. While her agents go to talk to the suspect the building they are in explodes and her team dies. It is revealed they died at the hands of a suicide bomber. Cassidy feels responsible and handles the loss terribly. Later in the episode member of a Muslim peace group ask to go back to the scene of the bombing to commemorate there friend that died in the bombing. Gibbs, DiNozzo, and Ziva go to protect the group and Cassidy is told to go to commemorate the loss of her fallen agents. Suddenly out of nowhere another suicide bomber emerges from a secret door. Cassidy without hesitation tackles the bomber. The door behind them closes and Cassidy and the bomber wrestle on the ground. During this segment Cassidy sees ghosts of her former teammates she lost just before the bomber presses the trigger and explodes. Agent Cassidy sadly dies. The entire team mourns her death especially Dinozzo who was the closest with her.