'How to Get Away With Murder' Boss Warns Not to Rule Anyone Out as Wes' Killer 

'How to Get Away With Murder' Boss Warns Not to Rule Anyone Out as Wes' Killer

"I want to keep people guessing until the end," Pete Nowalk tells THR about the second half of season three.

[Warning: This story contains spoilers from Thursday's midseason premiere of

's third season will be structured slightly differently as the Keating Five — now the Keating Four — investigate the murder of one of their own and try to figure out who killed Wes.

"Instead of flashing forward we'll be flashing back," showrunner Pete Nowalk tells

"Mostly we're going to see what happened before Wes died. And of course there's the questions of [who's] the killer and where were people when? That's always part of the show for me, piecing together the [timeline]."

Although Frank (Charlie Weber) seemingly confessed to the crime at the end of the midseason premiere, it's not quite that simple. "It can't be that easy, no," Nowalk says. "I think Frank made a very quick decision — he didn't even tell Bonnie — and whether he's telling the truth or not I don't think the police are going to necessarily want to believe him. They clearly have announced that Annalise Keating is their suspect.”

Annalise (Viola Davis) is currently in jail for the murder, and is now counting on her students — the one’s she’s coached (and manipulated) for the past year or so — to get her out. “She's going to sink pretty low. I think that was the appeal for me and I think that was also the appeal for Viola,” Norwalk says of writing Annalise’s downward spiral, which he notes has only just begun. “I want to watch Viola do everything. [Annalise] was arrested, and it makes a lot of sense for her to be in jail and not a lot of sense for her to get out any time soon.”

While the first half of the season saw one cast member revealed safe each week — or so people might've thought (such as that time it seemed like Wes 

the one under the sheet) — things won't necessarily be quite as obvious in the second half. "It's not going to be as clean as, 'You can rule out this person.’ I think it's more that you're going to start to get the full picture of the night," Nowalk says. "I want to keep people guessing until the end."

All four remaining members of the group — Laurel (Karla Souza), Michaela (Aja Naomi King), Connor (Jack Falahee) and Asher (Matt McGorry) — will deal with their grief differently, especially Laurel, who revealed that the dearly departed Wes is actually the father of her baby.

"Laurel has a lot on her shoulders. I think she's going to be dealing with it in her own time," Nowalk says. "What I love about getting to write something like this is they all have such different reactions. Obviously Connor's reaction, as you saw, was hard. I think they all have different suspicious about who did it; I think they all have secrets; and I think they all mostly have trauma."

But that doesn't mean any members of the Keating Four should be presumed innocent. Can any of them be ruled out as the killer? Warns Nowalk, "I wouldn't!"

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