Adam Rodriguez's title as the Criminal Minds newbie didn't last long. Damon Gupton joined the show in September as Agent Stephen Walker, two months after Rodriguez came on board as Agent Luke Alvez -- and just when Garcia (Kirsten Vangsness) finally took a liking to Alvez (and his dog).

"One of the jokes on set is that I'm the new newbie," Gupton tells TVGuide.com with a laugh. "I doubt he's jealous I took that!"

Gupton's casting, of course, came after Thomas Gibson's firing in August and unfurled nearly as quickly as the drama surrounding Gibson's dismissal following an altercation with writer/producer Virgil Williams. "I was doing a play here in L.A. and I got a call about meeting the great Erica Messer [the showrunner]," Gupton says. "I met her to talk about the opportunity and it worked out. About a week and a half later I was part of Criminal Minds, which just kind of shocked me. It happened so quickly, but I couldn't be happier to be around such a good group of people."

Being the new guy on a long-running show is hard enough, but doing so in the wake of a beloved original star's firing is hardly enviable. Still, Gupton says he had "no trepidation" about joining the show during such upheaval and with a segment of fans leading a #NoHotchNoWatch campaign.

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"It's more exciting to step into the world and see how I fit into the world and if I can bring something," he says. "The people who have come and gone have been such wonderful performers and flavors on the show. It's quite an honor to ask to bring something new to the table. You never want to disappoint fans. The show has such a huge fan base and you want to respect what's been created over the years and fan loyalty. I'm just excited to bring something new."

Easing the process is the fact that Walker is not a direct replacement for Gibson's Hotch -- Prentiss (Paget Brewster) has deservedly succeeded him as BAU unit chief -- and the show did a soft launch with his introduction in the final minutes of the Dec. 14 episode.

Damon Gupton, Criminal MindsDamon Gupton, Criminal Minds


Cool, casually confident, Walker is a longtime FBI agent and an old Interpol colleague of Prentiss' who was handpicked by her to join the team. "[The introduction] was brief, but on Twitter people have welcomed me and have supported me through other cast members and everything," Gupton says. "We'll see how that goes, if that grows."

Viewers will learn more about Walker on Wednesday's episode, which features the return of Rossi's (Joe Mantegna) foe Tommy Yates (Adam Nelson) as he teaches another profiling course. Walker, it turns out, was one of those young minds Rossi molded back in the day. "Rossi was his teacher at the academy. He taught a profiling course and he thought Stephen was a very talented profiler, so he's thrilled to see him join the team finally," Gupton says. "I think he's learning about Yates as he goes. It's a certain case he may have been briefed on at some point [by Rossi] back when, but not to the extent to being fully with the BAU."

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Walker hails from the Behavioral Analysis Program, the counterterrorism division of the FBI, so there will be a little adjustment period. "There's certainly not as much serial horror there as the BAU tends to go through week to week," Gupton quips. "He's loyal. He fits right in. He knows his stuff. He's a little more cerebral than I am. He's very competent and I think while he may seem quieter, he's in control of things. I think his experience crafted with Emily Prentiss at Interpol in London has given him great weight. He's eager to learn new skills with the BAU."

What Walker lacks in profiling at the moment, he makes up for with his spy-hunting background. Perhaps those tech-savvy, surveillance skills will prove to be vital when it comes to nabbing Mr. Scratch (Bodhi Elfman) and the remaining three unsubs on the loose, since Scratch has shown he's not above anything -- impersonation! flying nails! -- to taunt the BAU.

"In speaking with a real-life member of the BAP, I think some of the things the counter-surveillance and counterterrorism teams have in terms of access to technology are new as well, so we get to see some of those things come out," Gupton says. "Some of those things are some of the most important elements that he brings that are a little new."

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Walker has "no experience" with or a vested interest in Scratch before joining the BAU, Gupton says. But with Scratch seemingly targeting each member separately, he might have a personal stake in the hunt soon.

"Scratch has not targeted him... yet," he teases. "Who knows with that guy? That's a very dangerous guy, Mr. Scratch. [Walker] becomes deeply involved just by association. The hunt intensifies and he contributes as best he can. Hopefully! I think we'll be seeing more of Stephen Walker relatively soon."

Criminal Minds airs Wednesdays at 9/8c on CBS.

(Full disclosure: TVGuide.com is owned by CBS.)