Treat Williams, Samaire Armstrong and Kevin Pollak have signed on to the Lifetime original movie, The Staircase Murders from Lionsgate.

The film is based on the real-life murder case involving novelist Michael Peterson, who was accused of killing his wife in their North Carolina home. The Hollywood Reporter says Williams will portray Peterson, a loving father, and picture-perfect husband to his socialite wife, Kathleen. But when the panic-stricken author frantically calls 911 to report that Kathleen has accidentally fallen down the stairs, investigators discover several suspicious findings and begin to question how she died. Armstrong will portray Peterson's stepdaughter Caitlin, who breaks rank with the family to publicly accuse him of murder, while Pollak will play his lawyer, David Rudolf, who also begins to question his client.

Production is under way in Louisiana with director Tom McLoughlin; The Staircase Murders will premiere in April on Lifetime.