Jimmy Palmer's Entire NCIS Backstory Explained

Some fans of "NCIS" probably barely remember a time when autopsies weren't handled almost exclusively by NCIS Chief Medical Examiner Jimmy Palmer (Brian Dietzen). After nearly 20 years on CBS, "NCIS" has, of course, made a number of changes to its lineup of agency personnel along the way. The role of NCIS chief medical examiner is originally held by Dr. Donald "Ducky" Mallard (David McCallum). Ducky retires from autopsy in Season 16 after many years in the role, and Palmer immediately takes over the more senior role. Meanwhile, Ducky still regularly appears in "NCIS" in the newly created role of NCIS historian.

From his first appearance as the agency's newest hire at the end of Season 1 to his latest appearances in Season 19, Palmer has proven to be one of the series' most enduring characters. The only actors to be credited in more episodes of "NCIS" than Dietzen are Mark Harmon, McCallum, Sean Murray, and Pauley Perrette. Dubbed "Autopsy Gremlin" by NCIS Special Agent Anthony DiNozzo (Michael Weatherly), Palmer largely appears on the periphery in his first few seasons on the series and as a matter of convenience so that Ducky has someone to regularly talk with (other than the deceased Navy men and women who appear on his table). Over the course of his 320 or so credited appearances on the series (via IMDb), however, Dietzen has shown audience members that there is a lot more to Palmer's character and backstory than originally meets the eye. 

Brian Dietzen first appears as Jimmy Palmer on "NCIS" after the resignation of Ducky's original assistant, Gerald Jackson (Pancho Demmings). Gerald quits partway through the first season, following the group's second encounter with Mossad agent turned terrorist — and Cote de Pablo's character Ziva David's half-brother — Ari Haswari (Rudolf Martin). After being kidnapped twice by Ari, Gerald suffers a debilitating gunshot wound to the shoulder during their second meeting. 

Though he is said to be recovering in rehab, Gerald never returns to his job, and Palmer assumes his duties on a temporary basis when he joins the series in Season 1, Episode 21. His first scene introduces him with Ducky in autopsy, operating as a largely inefficient note taker for the elder medical examiner. Shortly after noting Palmer's habit of simply repeating everything he says, Ducky excuses Palmer from his first on-screen autopsy so that he can take a call from his mother. 

Palmer also appears in the final two episodes of the series' inaugural season. In his second appearance on "NCIS," Ducky promotes Palmer to his full-time assistant, despite openly noting the latter's tardiness to work that day. Though Dietzen is only a recurring character in Season 1 of "NCIS," he has appeared as a series regular in every season since.

Long before Palmer's late wife, Breena (Michelle Pierce), begins showing up around the NCIS office, Palmer briefly dates NCIS Special Agent Michelle Lee (Liza Lapira). Lee first appears in the Season 4 premiere, an episode titled "Shalom." Though Lee and Palmer begin dating in the middle of Season 4, the rest of the NCIS team doesn't find out about their romance until Season 6, shortly after Lee is revealed as a mole within the agency. Palmer feels obligated to inform the rest of the team of their short-lived affair in light of her betrayal. The rest of the team admits that they are already aware of her and Palmer's past relationship, and that they know he played no part in her leaking of classified material. 

Though Lee is covertly leaking information outside NCIS for some time before her death, she is ultimately revealed to be acting under duress as a result of the kidnapping of her younger adopted sister, Amanda (Tiffany Espensen). After months of secretly working as a double agent, Lee opts to turn triple agent and begins working with NCIS to take down the group that has her sister. In the course of her undercover operation, Lee is taken hostage by her handler. While struggling over a gun in a crowded subway, she gives Gibbs (Harmon) permission to shoot through her in order to eliminate the man. Sadly, the gunshot wounds prove fatal to both.

Arguably the most Palmer-centric episode of "NCIS" is Season 14, Episode 13, "Keep Going." Shortly after arriving with Ducky to collect a body, Palmer notices a man standing on the edge of a tall building overlooking the crime scene. Without alerting his NCIS colleagues, he rushes into the building and races up the steps in order to confront the man who is contemplating suicide. Not long after Palmer departs the scene, the rest of the NCIS team make the same realization and follow suit, unaware that Palmer has already joined the man on the ledge. Upon seeing Palmer on the ledge, Gibbs offers a simple, "Palmer, what are you doing?" to which Palmer replies, "I don't know." 

To help convince the troubled man to come inside, Palmer tells him about his wife and daughter, assuring him that he too has something to live for. Palmer also tells the young man about some of his own struggles to accept his place in the world, even confiding in him about his relationship with Gibbs, as well as Gibbs' past. Unbeknownst to Palmer, Gibbs listens to the entire conversation and takes note of the things Palmer says. At the end of the episode, Palmer is able to convince the man to cease his attempt to take his own life.

If you or anyone you know is having suicidal thoughts, please call the National Suicide Prevention Lifeline​ at​ 1-800-273-TALK (8255)​.

"NCIS" fans were treated to two Palmer-led episodes in March of 2019. In Season 16, Episode 16, Palmer struggles to deal with inappropriate requests from his father-in-law, Ed Slater (Larry Miller), who asks that he interfere in a murder investigation. Palmer acquiesces to the requests, but the stress of the situation leads him to snap at Ducky in an uncharacteristic manner. He later admits his failure to Ducky and apologizes, adding that he feels that he has brought shame on his profession. Ducky tells Palmer he completely understands the stresses that he has been working under. Ducky also adds that Palmer is an honorable man and that such worries are needless. The episode ends with Ducky telling Gibbs that it is time that Palmer take over permanently for him. 

The next episode ("Silent Service") begins with Ducky's last day as NCIS chief medical examiner. Palmer struggles to find an adequate way to thank him for everything and say goodbye, apologizing effusively throughout the course of the day, much to Ducky's chagrin. For Ducky's final day in the role, Palmer originally plans on giving a speech, organizing a picture slideshow, and baking cookies, while Ducky insists that his three-page letter and numerous gifts will be sufficient. In Season 19, Episode 5, Ducky briefly returns to assist Palmer in autopsy. In the same episode, however, Ducky realizes that he needs to leave Palmer to his job, noting that "yesterday is over."

In Season 18, Episode 7, "NCIS" shocks fans with the reveal that Palmer's wife, Breena, dies of COVID-19 during a time jump. Seeing such a tragedy befall a kind-hearted figure like Palmer leaves many viewers reaching for their tissue boxes, in what many fans consider to be one of the saddest moments in "NCIS" history. Palmer works hard to control his grief, even going so far as to triple his time at work and double down on his lighthearted nature. Though his dedication to his duties in autopsy help to distract him, those who know Palmer best can clearly see that the traumatic loss is taking a heavy toll on him.

In his time of intense sadness, Palmer turns to Gibbs, someone with a deep and painful knowledge of such loss, for help. Gibbs tells Palmer that he is stuck in the first phase of grief — denial — and that he recognizes such symptoms because he went through it too when his wife and daughter were murdered. Decades after their deaths, Gibbs admits that he is still going through the third stage, anger. To help Palmer, Gibbs simply listens to Palmer talk and hugs him. Ultimately, the NCIS team realizes that Palmer needs a method to publicly grieve the loss of his wife. At the end of the episode, Palmer eulogizes Breena while surrounded by his colleagues in the NCIS bullpen.