Petty (pictured below) will play an assistant medical examiner while Moynihan takes over as a forensic analyst. Their additions to the cast were announced during the series' TCA panel, which included former NCIS lead Mark Harmon, who is executive producer and narrator of the prequel. Showrunners are Gina Lucita Monreal and David J. North.
Also on stage was Harmon's son Sean, who appeared on NCIS as a younger Jethro in seven episodes from 2008-2020 and who first came up with the idea. He was asked to explain why he isn't playing his father's character (the role went to Bridge of Spies' Austin Stowell).
“It has been an honor to step into this world to play a character my dad created. It was always close to my heart,” explained Sean Harmon, who also holds an EP title on the prequel. “I never really wanted to make a career out of .. I was jazzed to step in to the executive producer role.”
NCIS: Origins begins in 1991, years before the events of NCIS. In the new series, Gibbs begins his career as a rookie special agent in the fledgling NCIS office at Camp Pendleton, where he earns his place in a tough team led by NCIS legend Mike Franks.
In the main series, Franks was a recurring character, played by Muse Watson. Franks was fatally stabbed in season eight, but continued to show up for Gibbs when he needed a sounding board on difficult matters.
Harmon said he won't be actively involved in the production, but he did play a role in finding the perfect young Jethro.
“When Austin came in, Gina swooned,” quipped Harmon.
Stowell said he didn't get a chance to talk to Harmon before auditioning. That didn't matter in the end, because this Gibbs is very different from the one the audience came to love in NCIS.
“This is Gibbs dealing with the loss of his wife and child. This is not the Gibbs that the world knows as the team leader who’s always put together,” explained Stowell. “This is someone who is broken, who is trying to find his identity. Mark did come up to me and said two words, ‘trust yourself.'”
Petty is known for her role as Lolly Whitehill in Netflix's Orange Is the New Black. In 2021, she starred in the dystopian HBO miniseries Station Eleven. Petty also guest-starred on CBS's Hawaii Five-0, Netflix's Obliterated, Fox's Gotham and Fox's Prison Break, among others.
Moynihan played the role of Jayden Kwapis in the NBC comedy series Mr. Mayor, starring Ted Danson, and had a guest role in TBS's Miracle Workers (2019). Moynihan also does a lot of voice work and you can hear his voice in Disney Channel's Star Wars Resistance, Disney XD's DuckTales (2017) and Paramount+'s Star Trek: Lower Decks, among others. He can currently also be heard as Forgetter Bobby in Pixar's cinema success Inside Out 2.
NCIS: Origins premieres Monday, October 14 on CBS.