NCIS' Brian Dietzen Shares What To Expect From Season 20 - Exclusive Interview

Heading into its 20th season in 2022, "NCIS" is still going strong as one of the longest-running scripted American prime-time television series in history, despite losing founding star Mark Harmon during the previous season.

The departure of Harmon as Special Agent Gibbs leaves the flagship "NCIS" series with just three main cast members dating back to Season 1: veteran actor David McCallum as Dr. Donald "Ducky" Mallard, Sean Murray as Agent Timothy McGee, and Brian Dietzen as Dr. Jimmy Palmer, whom Looper spoke to ahead of the Season 20 premiere that airs tonight on CBS.

As Jimmy, Dietzen plays the Chief Medical Examiner for the "NCIS" team, a highly trained group of Washington, D.C.-based agents who investigate crimes connected to Navy and Marine Corps personnel. In recent years, Dietzen has had to say goodbye to Harmon, Pauley Perrette, and Michael Weatherly and hello to Wilmer Valderrama, Gary Cole, and Katrina Law, who portrays Jimmy's new love interest on the show.

During our recent exclusive interview, Dietzen discussed the departure of Harmon, Jimmy's budding on-screen romance, and what to expect from Season 20 of "NCIS."

We're heading into the 20th season of "NCIS," and you've been on all of them. What does Jimmy Palmer mean to you?

Jimmy Palmer's meant a lot. I've known this character and been this character my entire adult life — I've grown up and had two kids throughout. But for me, the character has always meant optimism. He's always been an optimistic character. Had I been playing a character who's pessimistic or looked at life through a darker lens, I'm not sure I would be still playing this character right now. It's a pleasure to put on his shoes.

Season 19 ended on quite a cliffhanger, both in terms of Agent Parker and office lovebirds Jimmy and Jessica. What can you tell me about the Season 20 premiere when it comes to those storylines?

Both last year's finale and this year's premiere push "NCIS" toward what we do best. The premiere is basically saying, "This is 'NCIS' at its best, which is when the characters look after one another." We're all looking out for Parker because he's running across the country with his ex-wife, and we're not exactly sure where she stands. As a team, we have to gather around, circle the wagons, and try and help our guy.

As for Jimmy and Jessica, it's been wonderful to see their relationship [develop] and see them get closer, especially during the last couple episodes of last season. What I've loved about it so far is that we get to see two people who see something in one another, and they want to know what it's all about. There's less of a mystery there, less of a "Oh my gosh, what might happen?" It's just two people who are saying, "Hey, let's see if there's anything here." It's going to be exciting to see what happens between the two of them.

Where do you hope their love story goes?

I know a lot of where the love story is going and where the relationship is going, and I like what's happening with it. To see two people who are co-workers on a television show have a healthy adult relationship with one another can be refreshing. There's a tried-and-true relationship mechanic on many different TV shows, which is "will they, won't they." Seeing each other from across the room and trying to draw that out as long as possible. It's tried and true for a reason — because it does work. But it's nice to see people be happy with one another sometimes, and that can also help deepen friendships and relationships amongst the rest of the team.

I'm hoping that it goes toward that direction, which would be a nice change around "NCIS." There's been a lot of loss and a lot of heartbreak amongst romantic relationships in the past, whether it be on screen or off. Vance's wife, Jimmy's wife, Tony and Ziva, Bishop and Torres, Sloane and Gibbs — there's a lot of heartbreak, a lot of kisses on planes before people leave, and it would be nice to see something that's celebrated and perhaps lifted up.

On your Instagram, you posted a picture of Jimmy's glasses and a comment like, "Let's do this." It made me wonder, do those glasses help you get into character? Do you ever think of yourself as Clark Kent when you put them on?

Yes, absolutely. [Laughs] My wife pointed out one time when she came up to set, and I was getting my wardrobe on — I basically get to wear pajamas to work every day in scrubs — and I put the glasses on, which I don't wear at home. She looks at me and says, "Man, it really is the glasses. That changes a lot." I started laughing.

It's a little signifier. I got those glasses when I was 15 years old, and I've had them for almost 30 years now. I put them on and it's a little trigger that I can feel Jimmy Palmer taking over a bit. But they've become so iconic for the character that at the top of each season I like to take a picture of the glasses and say, "We're starting up with these things."

How did your own glasses get involved in the show?

I had an audition for a one-day guest star on "NCIS" in the first season, and I wore reading glasses at the time, but I couldn't find them anywhere. I went and got my backup glasses, which were these little Harry Potter-type glasses that I got when I was 15 years old — before I knew who Harry Potter was — that were the same prescription. I was like, "Okay, I can read with these, so I'll put them on." I went into the audition, and I booked the role and they said, "Bring those glasses with you." So I did. Then they said, "Can you come back next week?" I've been doing it ever since.

What do you think is one thing fans might be surprised to learn about Jimmy that they don't already know?

What do they not know about Jimmy? It's been 20 years and he's bared a lot for the audience. It was interesting that early on, we established that he's not a fan of baseball. I'm not sure why. It's probably because of the pitcher Jim Palmer, and the fact that he got called "Jim" once in a while when he was young. There's something — he doesn't like being called "Jim." Doesn't like "James" too much either. "Jimmy" is something that he's pushed for because it suits his personality more. If you ever see Jimmy Palmer on the street, don't call him "Jim." He won't turn around. It's got to be "Jimmy," or "Dr. Palmer" if it's Ducky.

Going back to the actors that have left the series over the years, including the biggie most recently, Mark Harmon — what's it been like on the set without him?

It's a massive change. This whole television show has been built on the backs and the effort and the work of people like Mark Harmon, like Cote de Pablo, like Michael Weatherly, like Pauley Perrette. There's a lot of people that have made this thing the entity that it is, that have served their time, or however you want to put it. They've been family members, and Mark has certainly been the patriarch of this family for 19 solid years.

You feel that loss right away on an energy level, but also on a personal level day to day — and on a story level as well, because everything must shift as the entire "NCIS" cast is no longer orbiting around this one central figure anymore. Those stories have to become much more ensemble than they ever have been before, which is what our show experienced last year.

On a personal note, I'm really thankful I got to work with Mark and call him a friend for that many years. I feel similarly about everybody I've worked with there. It's been a wonderful, wonderful place for 20 years. As people come into our set and people go, it feels like you're making new family members and you're making new friends all the time.

Do you have any good behind-the-scenes Mark Harmon stories you can share?

I remember one time early on, I had dislocated my shoulder. It was the second season, and I hadn't told anyone about it because I was a recurring guest star. I didn't want to make waves and be like, "I need time off" or "I can't do this or that." I was like, "It's fine, I'm going to have surgery in a few months on it." I could still move it and everything, but it would pop out once in a while. I remember one time Mark put a big 40-pound sandbag in my medical examiner kit, and I didn't know that. I went over and I lifted it up and went, "Oh, God." He didn't know [about the dislocated shoulder], obviously.

We did the take, and afterwards, I went over and talked to him and said, "I actually had a dislocated shoulder." He was like, "Oh, God, oh no!" He was very, very sweet about it. But that's the thing — on a set where you're sometimes working 14, 16, 18 hours a day, you've got to keep things somewhat light. You've got to smile a bit and play around. Not that we're goofing off the entire day, but you have to make things light, otherwise it can get a little arduous. He always has been very good at that. We've carried on in that spirit for sure.

What about the rumor that another past cast member, Pauley Perrette, might return in some capacity this season?

No, I have not heard that. I talked to her over the weekend, and I've not heard anything from her. I do know that in this new script I was just reading, there's mention of her character — not necessarily her, or anything like that. But that's the beautiful thing about the show. We can make mention of past characters that are no longer on the show and reference those people as you would a family member who no longer lives in the same house. You still talk about people. They're still in your heart. I love that there's a potential for that, but I haven't heard anything directly about her returning.

I think your Twitter picture with her may have sparked the rumor a little bit ...

Really? Well, that was one of those things where you work with someone for over a decade, so you're still going to hang out with them. You're still going to see them and go out for lunch here and there. I'm fortunate I get to still hang out with her and whatnot, but from everything she's told me, she's retired.

Fair enough. What kind of scenes or lines make for funny or memorable moments on set? Does anything stand out from the scripts, where when you see it coming down the pipeline you're like, "This is going to be a good one"?

I don't think that there's anything that's very specific, like, "Oh, whenever I have a scene with this actor, it's going to be fantastic." It's more so some of the odd pairings that are great. Some great stuff is born out of seeing people interacting that don't do it on a daily basis, because it's not the same thing that we see every week, whether it be in the bullpen, or the lab, or the autopsy room, or up in Vance's office.

The cast that we have right now is a tremendous group of actors — [they're] really good. The writers that we have right now, many of them have been with us nearly as long as I've been on the show. Some of them really have this cadence down. I love my one-on-one time with any of my actor friends on this show, whether it's Sean [Murray] or Wilmer [Valderrama] or certainly Katrina [Law]. Then there's Jimmy and Kasie. We have a wonderful time every time we're in one another's labs.

This last year has been great because I've gotten to establish a new dynamic between Jimmy and Parker [Gary Cole], which has been fun. He brings an entirely different energy than Gibbs did when he comes down to autopsy to look at findings. But I don't know if there's [anything] specific as to what makes for a good one. I do know that this show feels more collaborative than ever, and it's been great to get on set and say, "Let's see what works the best."

It's been awesome. We've been having a great time. I will say that one thing I haven't seen yet is a good Jimmy and Vance storyline, because those two are at opposite ends of the [office]. One's in a suite up top, and one's in the very lowest basement. Rocky [Carroll] is a very good friend of mine, so I'd love to see a little bit more of that.

What's been your favorite "NCIS" storyline so far?

It's not a favorite, but it's been most impactful for me — Jimmy losing his wife, Breena, who he'd been married to for nine years. It was impactful because a lot of people during that time period [at the height of COVID] lost loved ones, and Jimmy had to go through that as well. While that means I didn't get to have any more scenes with Michelle Pierce, a tremendous actor and wonderful person who played my wife, it was very impactful for me and for a lot of people that watched the show.

I was happy to be able to write an episode last year where I got to bring her back for a dream sequence and have what I felt was a bit more of a proper goodbye. That said, if I go back beyond that, some of the arcs that really affected me were the death of Ziva's father. The death of McGee's father also got to me. When Abby Sciuto was being stalked by someone, that was really powerful, and everything that involved Mike Franks and Gibbs. There are all of these great arcs over the history of the last 20 years. I'm excited to see what we're going to do next.

Do you wish there was a storyline your character would tackle that he hasn't before?

I don't think so. I feel as though they've given Jimmy Palmer a lot to do, a lot to explore. Whether it's putting him in danger or putting other things on his plate that he hasn't experienced before, and now having a potential love interest, it feels as though the character is having a lot of different experiences. Maybe a few years ago, I would've had a different answer, but as of right now I wouldn't say, "I wish they'd do more with this or that." At this point, I'm saying, "These writers are doing a fantastic job, and I would love to see whatever is in the next script."

20 seasons is a long time and a very respectable run, but all good things must come to an end at some point. What do you think a fitting ending for the show, or your character, would be? Have you thought about that at all?

We're halfway there; Season 40 is when we'll stop. It's probably going to happen with Jimmy's retirement ... No, I have no idea. The cool part is, if you asked our writing staff or the other actors on this show, you wouldn't get any similar answers, because I don't think any of us are focusing on the ending of the show, considering what the ratings still are and how much fun we're still having.

In my estimation, I'm like, "Let's keep concentrating on those great arcs." If the time comes — because, as you said, everything will come to an end at some point — one of those arcs is going to lead us to the Promised Land and to the "NCIS" ending. But if the ratings continue to be what they have been over the last year, I don't see that happening imminently.

Season 20 of "NCIS" premieres tonight, September 19, at 9 p.m. ET/PT on the CBS Television Network and is available to stream live and on demand on Paramount+

This interview was edited for clarity.