NCIS is one of the longest-running and most successful shows in the history of network television, and throughout 22 seasons, the series has seen a collection of diverse and interesting characters. That's always the core strength of any long-running network TV show, and NCIS is no different. What keeps audiences coming back season after season is the attachment they form to the characters and the chemistry of the NCIS cast.

Some of that love for characters is because they have been well-developed and fleshed out, with compelling backstories and arcs, while for others, it was that they brought such interesting story opportunities to the show. However, no series on air for so long is perfect, including NCIS, having just wrapped season 22, so there are also occasions in which characters were underutilized or fell victim to wasted potential, which forever tarnished their time on the show. Unfortunately, the way to resolve it has often been killing them off, leaving them with unresolved or unfulfilling arcs.

10 Agent Michelle Lee

One of the most divisive characters in NCIS, Agent Lee ed the team between seasons 3 and 4 before being outed as the mole in NCIS season 6, killing two agents in the process. However, it was revealed that she was forced to work against the team after her sister Amanda was kidnapped. Ultimately, Michelle allowed Gibbs to shoot her dead to help the gang take down Weatherman, and she died a hero. Michelle was both a hero and a villain, and her complex and flawed character made her an interesting addition to the show, which is why it was a shame when her time ended. She certainly deserved better.

9 Ned Dornegat

Ned "Dorney" Dornegat was first introduced in season 9 as a probationary officer before working his way up to NCIS Cyber Operations. He had a fun relationship with DiNozzo, and a complex relationship with his mother, Joanna Teague. Dorney met his end in NCIS season 12, when he helped the MCRT track down a terrorist cell that was recruiting children. He died a hero, saving multiple people during a terror attack in Cairo, and was killed during an explosion. Dorney was a strong addition to the team, but a character who could have been developed better, and his abrupt ending killed that potential.

8 Emily Fornell

Emily had one of the most tragic story arcs in the entirety of NCIS, and many fans are still angry with her character's treatment. Just a teenager when she first came on the scene in season 4, Emily experienced a number of tragedies over the course of the show. Her struggles with addiction were well documented and explored, particularly in the later seasons. Her father, Tobias Fornell, did so much to try to help his daughter, which made Emily's season 18 NCIS death even more tragic. The character deserved a break and some happiness, but unfortunately, it never materialized.

7 Mike Franks

A former Supervisory Special Agent, Mike Franks was a mentor to Gibbs, with the two having a strong connection. Brought out of retirement to help Shepard and Gibbs in season 3, Franks helped the MCRT bring down the Reynosa cartel. However, the fan favorite met his end in the NCIS season 8 episode "Swan Song" while going after the Port to Port Killer. Luckily, a younger version of the character appears in NCIS: Origins, exploring his backstory, but in NCIS, he was a character who deserved more.

6 Agent Brent Langer

Jonathan LaPaglia's underrated Agent Brent Langer was once mentored by Gibbs, and ed his new team following new NCIS director Leon Vance putting Gibbs in charge of a new squad. Unfortunately, Langer was shot and killed in the NCIS season 6 premiere, by mole Michelle Lee, who sought to conceal her role in the leaking of classified information. Langer was underused in the show, and could have been kept around for a couple of seasons as a great way of exploring Gibbs' character more closely, and developing a strong dynamic between the two.

5 Eli David

Eli David was the classic case of a character who was misguided. His single-minded obsession with defending Israel came at the expense of his children - radicalizing son Ari and endangering the life of daughter Ziva. He was eventually killed in a drive-by shooting by anti-peace operatives, but the character should have had a different fate. It would have been nice to see him fulfill his goals and patch things up with his kids, but his death in NCIS season 10 illustrated the dangerous nature of the world of NCIS.

4 Jackson Gibbs

Gibbs' estranged father had a difficult relationship with his son, and was first introduced in the show in season 6. Eventually, they began to repair their relationship, restoring an old car to fulfill one of Gibbs' teenage dreams. Leroy even began to call his father "Dad" instead of "Jack." Just as the pair began to forgive and set old wounds to rest, Gibbs was devastated to learn his father had died from a stroke in the season 11 finale. Jackson deserved to be kept around, but the fact that actor Ralph Waite ed away just three months later made this dream impossible.

3 Director Jenny Shepard

Despite being a divisive figure during her run on the show, Lauren Holly's Director Jenny Shepard was a strong and interesting addition to the team. NCIS's first-ever female boss met her tragic demise when the ghosts of her past caught up with her. Following her involvement in the death of arms dealer La Grenouille, whom she wrongly believed had killed her father, Shepard was eventually murdered in a shootout with a hitman sent by long-time nemesis Svetlana Chernitskaya. Jenny left an enduring legacy, and could have been in the show so much longer.

2 Special Agent Paula Cassidy

Though she only had a brief stint on the show, appearing in six episodes across four seasons before her death, Paula's death remains iconic and emotionally wrenching. Wracked with guilt after leading her team into a trap that claimed the lives of two agents, Paula made the ultimate sacrifice, tackling suicide bomber Jamal Malik in order to prevent another deadly explosion. It was a poignant ending for a popular character, and R.E.M.'s "Everybody Hurts" playing while the team mourns her loss was definitely a tear-jerker. But Paula deserved better, and her relationship with Tony DiNozzo could have been a long-term 'ship.

Paula appears in the NCIS season 12 episode 'The Lost Boys,' as a hallucination.

1 Special Agent Caitlin "Kate" Todd

One of the most shocking deaths in the entire franchise, Caitlin was the first core character to be killed off on the show, dying in the NCIS season 2 finale "Twilight." The Secret Service agent was assassinated mid-sentence by terrorist Ari Haswari, in the final few seconds of the episode, in one of the most heartbreaking scenes in the whole show. The character was killed off after actress Sasha Alexander's decision to leave NCIS due to the rigorous schedule of network television.

Kate's death remains one of the most memorable and iconic of the whole show, and is still mourned by fans to this day. One of the reasons was because of Alexander's powerful performance, a testament to the actor and her skills. So while it was great that Sasha Alexander got to leave on her own , storywise, it was still a crushing blow to audiences and the other characters. Her importance to the show and to audiences alike makes Caitlin Todd the ultimate example of NCIS characters who deserved better ends.

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