Toni Collette to star in HBO Max's The Staircase

Deadline

The Oscar-nominated and Emmy-winning actress will co-star with Colin Firth on the eight episode limited series based on the acclaimed true-crime docuseries of the same name. Collette will play Kathleen Peterson. Michael Peterson, played by Firth, was convicted of killing his wife Kathleen after he claimed she died falling from a staircase after consuming alcohol and valium, but an autopsy concluded she died from multiple injuries, including blows to the back of her head with a blunt object. Collette is an Emmy winner for Showtime's United States of Tara. She was also nominated for an Emmy for Netflix's Unbelievable. Collette also stars in the upcoming Netflix thriller series Pieces of Her.