This would also explain why Gary Cole has been brought aboard for a “major role” in Season 19.
Unfortunately, while traveling to a location where this serial killer might have visited in the Season 18 finale, Gibbs’ boat exploded, although he was seen in the episodes final seconds swimming away from the wreckage. While it’s reasonable to assume that we’ll eventually see Gibbs apprehend this killer, the news about him not having a heavy presence in NCIS Season 19 means fans should prepare for the possibility that he won’t resume his duties for the Naval Criminal Investigative Service.