Colin Firth’s Michael Peterson Tries to Prove His Innocence in New ‘The Staircase’ Trailer (Video)

The series debuts on HBO Max next month

Tensions are high in the official trailer for HBO Max’s “The Staircase,” as Colin Firth’s Michael Peterson character tries to convince his lawyers, a jury, and even his family that he didn’t kill his wife.

The well-documented case involves the death of Kathleen Peterson (played by Toni Collette), who was found dead at the bottom of the staircase in her home in December 2001. Her husband Michael was later convicted of her murder. He has maintained his innocence, successfully appealing for a re-trial before eventually taking an Alford plea (allowing him to accept his sentence without actually admitting guilt).

The upcoming series is a dramatized version of the events surrounding Kathleen’s death and Michael’s conviction. The full-length trailer, which you can watch above, begins with a seemingly joyful speech from Collette’s Kathleen as her family sits around the dinner table.

“I’d like to make a toast to so many better days ahead,” she says. “Every day is going to be an adventure. So always stop and think: This is one of the happiest days of my life.”

The video quickly cuts to a more ominous scene outside the Peterson home as police lights flash and crime scene tape hangs across the yard. Firth’s voice enters, re-enacting the 911 call Michael made the night of Kathleen’s death.

“My wife, she had an accident. She fell down the stairs,” he says. “She’s not breathing.”

In the series, Michael quickly becomes a suspect in the case, as investigators work to uncover the circumstances surrounding Kathleen’s mysterious and seemingly brutal death. As the case unfolds, seeds of doubt grow in everyone’s minds, including Michael’s kids.

In addition to Firth and Collette, the scripted show also stars Michael Stuhlbarg as Michael Peterson’s defense attorney David Rudolph; Patrick Schwarzenegger as Michael’s son Todd Peterson; Dane DeHaan as Michael’s other son Clayton Peterson; Olivia DeJonge as Caitlin Atwater, Kathleen’s biological daughter; Sophie Turner as Margaret Ratliff, one of Michael Peterson’s adopted daughters; and Odessa Young as Martha Ratliff, Michael’s other adopted daughter.

The first three episodes debut on HBO Max on May 5, followed by one new episode weekly.