Pauley Perrette played Abby Sciuto on NCIS for 15 seasons and left the show in 2018. In the show, her character resigned after an assassination attempt, but according to multiple reports, the real reason she left was because she had a falling out with series lead Mark Harmon. The two reportedly had a number of clashes behind the scenes in 2016 after Harmon brought his dog to set, where it bit a crew member leaving him needing 15 stitches. Tellingly, the pair did not share the screen together during Perrettes emotional final episode. Instead, Abby bid farewell to her other colleagues at NCIS HQ and simply delivered a letter for Gibbs and watched from the street as he read it.

Perrette did not initially provide a specific reason for leaving NCIS, but she did debunk that it was to start her own "skin care line" or because the network and show were "mad" at her. She later revealed that the decision to leave was made the year before. In Abbys last scene in NCIS, she waved goodbye to Gibbs across the street from his house after leaving him a note. So the two actors werent actually onscreen together when the characters had their final moment.

In September 2022, Perrette revealed that she had suffered a massive stroke a year prior. She left NCIS in 2018 and later starred in the short-lived CBS sitcom "Broke" before announcing her retirement from acting in November 2020.