The character Will LaMontagne Jr., played by Josh Stewart, left "Criminal Minds" because the actor decided not to return for the second season of "Criminal Minds: Evolution." Stewart officially confirmed his exit in January 2024 but did not elaborate on his reasons for leaving. The show's showrunner, Erica Messer, stated that they tried to make it work for the new season but couldn't reach a deal with Stewart. It is suggested that Stewart might have been busy with other projects or chose not to renew his contract. Will's character was written out by dying from an aneurysm early in Season 18, Episode 2, providing a story explanation for his absence. This departure affected the storyline significantly, as Will was an important part of JJ's character arc and the overall team dynamic.
