It's finally been announced! Pulled from Publisher's Marketplace:

JoAnn Chaney’s debut, WHAT YOU DON’T KNOW, about how seven years after a renowned serial killer was put in jail, those in his orbit – the cop who arrested him, the lead reporter on the case, and his wife — are sucked back into a new nightmare when an eerily similar series of murders occur, and this may be their last chance for vindication or finally cause them to forfeit what’s left of their humanity, in a two-book deal, to Amy Einhorn and Christine Kopprasch at Flatiron Books, by Stephanie Cabot at The Gernert Company (World).

Also, available to view here: