UPDATED: It’s never good news when the creator/showrunner of a successful series exits. That has happened on TNT’s flagship drama Rizzoli & Isles, with Janet Tamaro, who developed the series based on the novels by Tess Gerritsen and served as executive producer/showrunner on the first four seasons. The departure of Tamaro, who will remain as a consultant while developing new projects, comes less than a month after production on Rizzoli & Isles was shut down and the show’s writers had to regroup following the sudden passing of co-star Lee Thompson Young. It also comes just as production wrapped on Season 4. (The death of Young, who committed suicide during the filming of the second to last episode, will be addressed at the beginning of Season 5.) It follows persistent talk about discord on the Rizzoli & Isles set and speculation that Tamaro may depart. “This is what we all dream of getting to do,” Tamaro said in a statement. “And I got to do it for four phenomenal seasons. I’m at the top of my game, thanks in large part, to this unbelievable experience and show. It’s time to challenge myself and develop new projects. TNT and Warner Horizon have been a dream to work with, and I look forward to doing it again. The heartache for me will be leaving the day-to-day working relationship with an incredible cast and crew.” Under Tamaro’s helm, Rizzoli & Isles became TNT’s #1 show of all time, eclipsing The Closer. It ranks as the #2 scripted series in the history of ad-supported cable television, behind only The Walking Dead. Search for a new showrunner is underway.