Cook departed Criminal Minds after the end of last season when her option was not picked up, stirring outcry among fans of the show. She appeared in the first two episodes of this season to wrap the storyline of her character JJ, who was transferred from the BAU to a job at the Pentagon. Cook then returned for the last episode of the season for co-star Paget Brewster, which aired last month. If Brewster's NBC comedy pilot My Life As An Experiment does not go to series, she will also likely return to Criminal Minds in the fall since series' producer ABC Studios has an option on her. Cook's return to Criminal Minds does not bode well for newly minted regular Rachel Nichols, who was brought in to fill the void left by Cook's departure. Meanwhile, ABC Studios is yet to close new deals with original cast members Thomas Gibson and Shemar Moore for next season, with negotiations continuing.
Cook was offered to return to Criminal Minds late last week after the series' producers recently came up with ideas for JJ for next season. Despite her exit from the show, Cook and her character continued to be extremely popular among Criminal Minds fans. Heading into Season 7, Criminal Minds will be run solely by executive producer Erica Masser following the recent departures of executive producers Ed Bernero and Simon Mirren, who have served as co-showrunners with her this season.
ETA: AJ Cook tweeted and confirmed it!