Why 'The Walking Dead' Killed Off Its Latest Showrunner

Insiders tell THR that "very protective" comic book writer Robert Kirkman was one of many who clashed with now-fired Glen Mazzara.

This story first appeared in the Jan. 18 issue of The Hollywood Reporter magazine.

When a network fires two showrunners in less than 18 months from its biggest hit -- and one of the most successful franchises on television -- that is sure to make waves in Hollywood and with fans. So no matter how AMC tried to spin the Dec. 21 departure of Glen Mazzara from The Walking Dead as just one of those amicable things, insiders rolled their eyes -- especially because the network let go co-creator Frank Darabont in July 2011 and has had high-profile spats with writer-producers on its hits Mad Men and Breaking Bad.

AMC and Walking Dead comic book writer and producer Robert Kirkman were blamed for Mazzara's ouster and called out by name by showrunners Shawn Ryan (Last Resort) and Kurt Sutter (Sons of Anarchy), neither of whom is involved with Walking Dead but both of whom worked with Mazzara on Ryan's FX series The Shield. Ryan tweeted, "It's a real question now why good showrunners should sell to AMC," and Sutter followed with a tweet declaring that AMC had sent him "a gift basket filled with … broken promises and the marinated tongue used to lick Kirkman's ass."

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In a follow-up video posted on his website, Sutter denounced AMC for departing from a cable culture that generally allows showrunners more creative freedom than do the broadcast networks. Kirkman, he added, "is an amazing visual artist and a graphic artist [but] knows very little about TV, and the reins keep going back to him in this process, and he doesn't know how to run a show."

Several insiders confirm that Kirkman, whose detailed graphic novels form the basis of the series, is "very proprietary," as one puts it. One adds, "I believe Robert wants to maintain a certain amount of his control, and AMC needs Robert for the fan base." But despite the vitriol, some sources involved with Walking Dead say Kirkman was one of several producers on the show who had issues with Mazzara and his vision.

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One source says Mazzara's shortcomings in running the series during the most recent third season became "abundantly clear … especially for the second half of the season." This source says production was shut down "several times" because of a lack of material.

Mazzara declined comment but will participate in a Jan. 11 AFI awards luncheon that will honor Walking Dead as one of 2012's top shows. The midseason finale Dec. 2 lured 10.5 million total viewers and 6.9 million in the key adults 18-to-49 demo, crushing nearly all broadcast network shows.

To date, Kirkman has responded to the criticism only with a restrained tweet: "@sutterink is brilliant and Sons is my favorite show on TV. Still, it's upsetting to see him ranting about things he knows nothing about." AMC declined comment.