Ari Haswari was a rogue Mossad officer and terrorist who was also a sworn nemesis of Leroy Jethro Gibbs who tormented Gibbs and the NCIS Major Case Response Team for the first two seasons of the show.
In addition to having launched numerous attacks against the team, Ari, already a thorn in the team's side became a very dangerous threat that needed to be stopped once and for all when in the last few seconds of the Season 2 finale episode, "Twilight", he shot Agent Caitlin Todd in the head with a lone .308 round from a Bravo 51 sniper rifle that he was manning with the impact of the gunshot killing Kate instantly while leaving her NCIS colleagues devastated over her murder and Gibbs hellbent on avenging Kate's death at any cost and by any means necessary.
Ari's wave of terror which had started when he invaded the NCIS morgue, triggering a hostage situation and had continued on for nearly two years finally came to an end when he was ultimately killed in a confrontation with Gibbs and Ari's fellow Mossad Officer/half-sister Ziva David who later joined the team, officially and permanently replacing the deceased Kate Todd.
Ari Haswari was born in 1969 to Dr. Benjamin Weinstein (the undercover alias of Mossad agent and future Mossad director Eli David), and Dr. Hasmia Haswari, an Arab woman, while they were both doctors working together at a hospital in Jerusalem. Ari had two paternal half-sisters, Ziva and Talia "Tali" David. Ziva would later become Ari's control officer in Mossad, while Tali died in a Hamas suicide bombing at the age of sixteen.
According to Ari, from the moment of his birth, his father shaped him to be a Mossad mole inside Hamas. In 1994, Ari graduated from Edinburgh Medical College (the same alma mater as Donald Mallard).
After graduation, he did his post-graduate work at the Edinburgh Center for Infectious Diseases. He was described by his colleague there, Dr. Martin Sedgewick, as a brilliant ladies's man who answered only to his surname 'Haswari', and "never Ari."
Roughly four years prior to his first contact with NCIS, Ari's mother was killed during a retaliatory missile strike from Israel. Ari believed that Eli had orchestrated the strike on purpose: to give Ari a perfect reason for joining Hamas, while still working undercover for Mossad. In fact, Ari later turned against Eli, working as a double agent for both Mossad and a series of terrorist groups (including al-Qaeda) until he was in the perfect position to strike back at his father and Israel.
Encounters With NCIS
While working undercover as a member of Hamas, Ari was ordered to find the body of another terrorist named Qassam who had botched a plan to spread smallpox on the Norfolk Naval Base, a plot NCIS had learnt of after receiving evidence from Special Agent Paula Cassidy who was stationed at Gitmo. It was soon discovered that Qassam had intended to target a group of Israeli sailors who according to Special Agent Daniel Snyder were at Little Creek, training on hurricane boats.
Ari made himself known to NCIS by infiltrating the agency while hiding in a body bag that was taken to NCIS for an autopsy and upon emerging, shot out the video cinema before taking Donald Mallard and Gerald Jackson hostage.
Special Agent Caitlin Todd later arrived in Autopsy, unknowingly becoming the third hostage of the crisis with Ari demanding that the terrorist's effects be returned to him in exchange for the hostages.
During this time, Ari also shot Gerald in the shoulder in revenge for Ducky and Kate attempting to trick him. The wound, although not as bad as originally thought and thanks to Ducky's efforts stopped bleeding but the psychological trauma combined with the pain ultimately put Gerald into rehab for several months and would later cause him to resign from his position as Medical Examiner assistant for good. Ducky's assistant James Palmer who had originally taken on the role on a temporary basis later became the Medical Examiner Assistant on a permanent basis.
Ultimately, Special Agent Leroy Jethro Gibbs arrived in the morgue per Ari's request, carrying a box of the terrorist's effects, but revealed that Ari's true object -- the smallpox -- had already been confiscated. Ari was impressed with Gibbs's marksmanship for shooting the terrorist from such a distance, and offered him a chance to kill him. Gibbs took it, but was shot in the left shoulder instead and collapsed to the ground, drifting in out and of consciousness. The gunshot wound was a through and through and Gibbs's left arm was left wounded in the process. However in the ensuing invasion of Autopsy, Ari escaped by shooting two H.R.T agents, killing one while the other survived and while disguised as an H.R.T agent, managed to flee NCIS.
Gibbs was later seen in his basement, his left arm in a sling and then proceeded to shoot a picture of Ari and it was shown that the rounds from his gun had hit the photograph dead center, suggesting that Gibbs wanted to kill Ari. The entire incident created a connection between Ari and Gibbs, Ari coming to see the similarities between Gibbs and his father and coming to hate him for it, and Gibbs becoming obsessed with discovering Ari's identity by any means necessary although his need for answers later grew so strong that it began to concern his team, Kate in particular who believed that Gibbs was becoming fixated on Ari, believing the event had occurred only the day before, not several months ago.
After this encounter, Gibbs became obsessed with learning the terrorist's name and spent the next two months scouring different databases in search of who Ari was with his searches going nowhere and even proving fruitless at times.  It all seemed hopeless that was until Special Agent Timothy McGee who was stationed at Norfolk at the time of Ari's first appearance and who would be later transferred to Gibbs's team in Washington D.C on a permanent basis came up the idea to put new photos onto Gibbs's hard-drive in hopes of getting some answers. McGee's search eventually uncovered Ari's true identity along with key information regarding Ari's past.
A few months later, Ari returned to the U.S. as the head of a Hamas cell with the plan of kidnapping then-President George W. Bush and then-Israeli Prime Minister Ariel Sharon, who were in the midst of diplomatic talks. Ari kidnapped Agent Todd ostensibly so that she could disclose a method of revealing the Marine One helicopter during the transporting of Bush and Sharon to Camp David.
When Kate revealed that there was no way to tell the helicopters apart, Ari shot dead one of the terrorists, a Swedish woman named Marta in the head when she attempted to alert the members of Ari's cell of the development and revealed to Todd that he was actually an Israeli working for the Mossad.
Following these events and the revelation that Ari was working undercover in both Hamas and Al-Qaeda, the FBI permitted him to leave the country much to Gibbs's anger.
Before he left, however, Ari agreed to a private meeting with Gibbs, where he admitted that he shot Gerald Jackson in order to keep his cover with the terrorist groups he was working to undermine. Before the two men parted, Gibbs shot Ari in the shoulder in revenge for Gerald and Gibbs himself having suffered the same fate and to also "better convince Al-Qaeda" of Ari working against the U.S. and Israel.
- "Sorry, Caitlin."
- —Ari just mere seconds after killing Kate in the Season 2 finale, Twilight.
Over the next year, Ari's obsession with Gibbs grew much stronger and stronger until it finally got the better of him and he went on a vendetta against the special agent.
In early May 2005, while on assignment with the FBI to uncover an Al-Qaeda cell in Washington D.C. which he was running, one of Ari's men from the cell broke contact and disguised as a Virigina State Police Officer killed two Navy officers.
Then, knowing that NCIS would be called to the crime scene, Ari and the group planted a bomb on the car in order to kill members of Gibbs's team. The bomb went off, but no-one was killed thanks to the fact that DiNozzo had noticed it after being kicked onto the ground by Todd and had acted quickly, thus saving the lives of himself, Todd and Agent McGee although the car and the two victims were destroyed or rather burnt beyond any recognition, forcing Ducky and Jimmy to use dental records to get a positive identification on the two bodies.
Shortly thereafter, Ari attempted to kill Gibbs by planting a bomb in a coffee shop, and then orchestrated a terrorist attack against numerous ships of sailors returning from the Gulf to dock at Norfolk Harbor.
Having tracked Ari's location to a warehouse in downtown Norfolk, Gibbs and his team reached the scene in the nick of time and after a long and lengthy gunfight, were successful in stopping both attacks from taking place, but as they searched for the last of the terrorists while celebrating their success, having taken a moment to gather themselves after the intense gunfight, tragedy struck when Kate, having recovered after taking a bullet meant for Gibbs was shot in the head, the brutal force of the gunshot killing her instantly while also severing and destroying her brain upon impact. Abby's tests later revealed that the bullet responsible for Kate's death had come from a Bravo 51 sniper rifle which Gibbs later revealed was nicknamed "Kate".
To make matters worse, when Kate had been shot, both Gibbs and Anthony DiNozzo had been with her with the two witnessing her murder and Tony was even splashed with some of Kate's blood in the process. This began a sadistic cat-and-mouse game between Gibbs and Ari with Gibbs swearing revenge against Ari for Kate's death and vowing to go against the FBI and also the new NCIS Director Jenny Shepard to get Ari despite Shepard who, like many other agencies believed that Ari wasn't the murderer although Gibbs had seen him on the opposite rooftop just mere seconds after Kate's murder.
Several hours after Todd's murder, Ari attempted to kill Abigail Sciuto in her lab, but missed the shot thanks to DiNozzo's quick actions. Ari then spent the next two days leading Gibbs and his team on a wild goose chase throughout the city. Further complicating matters was the arrival of Ziva David, Ari's control officer and half-sister, who believed that Ari was a loyal Mossad agent and innocent of Todd's murder and the attempted murder of Sciuto. She worked with other Mossad operatives to pass money and a passport to Ari so that he could leave the country.
After an attempted assassination of Jennifer Shepard, the new NCIS Director, and the subsequent death of the terrorist believed to be responsible, Ari broke into Gibbs's house and waited for him to arrive home. Once there, Ari revealed his reasons for his actions, and explained that he had targeted Kate, Abby, and Jenny specifically to cause Gibbs pain.
In private, Ziva had revealed to Gibbs that she had investigated him and found out about the murders of his first wife and his daughter. Presumably, Ari likewise found out through Ziva, and knew how much it would hurt Gibbs if he failed to protect other women who were close to him.
- "Sorry to spoil your-."
- —Ari's final words just seconds before Ziva shoots him in the Season 3 episode, "Kill Ari Part 2".
Before planning to flee the U.S, Ari's last plan was to kill Gibbs with his own Marine Corps sniper's rifle, making it look as though Gibbs had committed suicide. As he raised the rifle, however, he was shot. It was later revealed that Ziva who had been listening from the doorway of Gibbs's basement the entire time finally realized that Ari was a rogue and a monster was the one responsible for killing Ari. It was later shown that in a twist of irony, much like how he had shot Marta and Kate in their own respective foreheads, Ari himself had been shot in the head as well. It was also later revealed that Gibbs had arranged the entire plan with Ziva's backing.
Gibbs's official report to NCIS stated that he, not Ziva, had killed Ari. The same report was passed on to Mossad although Gibbs and Ziva later kept it a secret.
Ari always believed that his father never realized Ari had turned against him. During his confrontation with Gibbs, he expressed regret that he would not be able to see "the bastard's" face when Eli realized he had created a monster.
However, four years after Ari's death, in a heated discussion with Gibbs, newly appointed 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.
Four months later, the NCIS team later received word of Ziva's death while on a mission for Mossad and went to North Africa on a mission of revenge with Tony leading the operation. In the process, both Tony and McGee were captured with McGee being knocked unconscious and Tony was given a truth serum by their captor, a terrorist named Saleem Ulman but they later discovered that she was actually alive, having been Saleem's prisoner for months. Eventually, Saleem was shot dead by Gibbs, allowing McGee and Tony to escape with Ziva before the four of them returned home to America. A while or so after the rescue, Gibbs later confronted Ziva. She admitted that she had been ordered to kill Ari, but had believed him innocent, and was going to sneak him out of the country instead, until she heard his confession in Gibbs's basement. She swore that when she shot Ari (who was, after all, her own brother), she was not blindly following Eli's orders, but doing it to save Gibbs. Gibbs appeared to accept this.
Despite being dead, Ari reappered in the episode, Life Before His Eyes (episode) in a diner resembling Gibbs's subconscious while also showing various characters of the past and present. In the diner, Ari was seen playing a game of chess with Leon Vance. In stock footage from Twilight (episode), it was shown that in an alternate reality, Ari had failed to deliver the one fatal shot that killed Caitlin Todd in real time due to his sniper rifle jamming and with air support bearing down on his position after being spotted by Gibbs, was forced to flee with his fate after this unknown.
Gibbs vs. Eli
Ari claimed that part of the reason he hated Gibbs so much was because he reminded Ari of Eli, whom Ari hated most of all. Though there are some superficial similarities in the two men's personalities, and they do physically resemble each other fairly well, in reality they could not be more different. Gibbs is devoted to his job, but his greatest devotion is to the memory of his family. Gibbs was sickened and enraged by a Navy Captain who staged his own wife and daughter's kidnapping for money. 
Likewise, Gibbs could not credit Ari's belief that Eli deliberately had Ari's mother killed, just to further his own plans for Ari. ,  Partly this may have been explicable by his distrust of Ari, but also because he could not believe any man would so callously use his own family for the sake of a mission.
Eli, by contrast, is obsessed with his mission of protecting his country, so much that he has raised his own children to be killers, and engaged in various underhanded schemes to ensure their continuing loyalty to him and to Israel. After getting a glimpse of these methods, it appears that Gibbs begins to believe Eli is as ruthless as Ari described.
Ziva, unlike Ari, sees the difference between the two men. Growing sick of her father's duplicity, she resigns from Mossad, says, "Eli is all but dead to me," and calls Gibbs "the closest thing I have to a father."
Though Gibbs ultimately despised Ari with all his heart, Gibbs felt sorry for Ari.
- Unnamed H.R.T. agent- (shot to death, later presumably stole his uniform which Ari used to escape).
- Marta- (shot through the forehead with Kate Todd's weapon).
- Lieutenant Dean Westfall- (shot in the chest and had his hands removed as well with his index finger later being used to help the terrorist group get a drone from a warehouse).
- Lieutenant Curtis Janssen- (gunned down in the back as he attempted to escape from the car, hands were also severed post-mortem).
- Caitlin Todd- (shot in the head with a round from a sniper rifle nicknamed a "Kate" which resulted in her death instantly).
- Timothy McGee- (twice attempted, first with the bomb and second time during the gunfight at the warehouse in Norfolk. It should be noted that McGee was Ari's original target but for some reason, Ari later spared his life, killing Kate instead).
- Anthony DiNozzo- (attempted, with the bomb).
- Abigail Sciuto- (attempted, fired a shot through her lab that would have almost certainly killed her if it hadn't been for DiNozzo's reflexes).
- Leroy Jethro Gibbs- (twice attempted, shot him in the shoulder in "Bête Noire" and later intended to kill with his own M40A1 sniper rifle in "Kill Ari Part 2").
- Ari suffered from Lepidopterophobia, the fear of butterflies.
- He graduated from the same school as Ducky, the University of Edinburgh's Medical school in Scotland although Ducky noted that there were a few decades between the two of them.
- In an alternate reality from Life Before His Eyes (episode), Ari was forced to abandon his chance at killing Kate after a chopper was sent to extract her, as trying to kill her then and there would have exposed him to the chopper. This scene was in fact based on an actual alternate ending to Twilight that was filmed, where she did survive.
- ↑ 1.0 1.1 1.2 1.3 1.4 Season 1, Episode 23, Reveille.
- ↑ 2.0 2.1 2.2 2.3 2.4 Season 3, Episode 2, Kill Ari Part 2.
- ↑ 3.0 3.1 Season 1, Episode 16, Bête Noire.
- ↑ 4.0 4.1 Season 2, Episode 23, Twilight.
- ↑ Season 3, Episode 1, Kill Ari Part 1.
- ↑ 6.0 6.1 Season 3, Episode 4, Silver War.
- ↑ Season 6, Episode 25, Aliyah.
- ↑ Season 7, Episode 2, Reunion.
- ↑ Season 2, Episode 1, See No Evil.
- ↑ Season 3, Episode 2, Kill Ari Part 2
- ↑ Season 7, Episode __.
- ↑ Season 1, Episode 16, Bête Noire