Showrunner Erica Messer informed in an interview that Cook's character JJ will not appear for the first five episodes of the season as Cook is on maternity leave. Messer continued talking about a guest star to replace Cook during her absence from the show as she said, "My hope is we could have a fun guest star when A.J.'s on maternity leave. It will be different because JJ won't be there. There is no replacing her as we know, but there's an opportunity there to have fun for a few episodes." Aisha Tyler will join the cast in the wake of Hewitt's exit, and will be playing a recurring role as Dr. Tara Lewis, a forensic psychologist who has always wanted to study psychopaths up close, to understand the human being behind the evil acts. Her previous job was to interview serial killers and determine whether they were fit to stand trial. It was announced that Tim Kang will guest-star on the show in the second episode of the season, "The Witness". while Marisol Nichols is set to make an appearance. It was announced on August 5, 2015, that an alum from "Glee", Ashley Fink, will guest star in the third episode of the season, "'Til Death Do Us Part". Amber Stevens returned as Rossi's daughter, Joy Struthers, in episode seven, "Target Rich". Aubrey Plaza also had a guest role in episode eleven, "Entropy". On January 14, 2016, CBS announced that actor Danny Glover will guest-star as Derek Morgan's deceased father in the episode "Derek". On February 10, 2016, CBS announced that actor Paget Brewster will guest star in one episode in the latter part of the season, reprising her role as Emily Prentiss. In an interview with "TVGuide", Erica Messer expressed her interest about bringing back characters from previous seasons instead of adding a new character to replace Hewitt permanently on the show. She explained, "I feel like when you look at 10 years of people we could bring back, it would be fun to do that." Messer added that bringing back old characters would allow the show to focus on the team without having to service a new regular character.