While many true crime movies and series tell a story from the perspective of the case itself, HBO Max’s limited series, The Staircase also digs deep into the viewpoint of the Peterson family, who are shaken to their collective core when father Michael Peterson (played by Colin Firth) is implicated in the death of his wife Kathleen (Toni Collette).

Sophie Turner, who plays daughter Margaret, points out that while the audience finds out right away “where [the Peterson kids] stand in terms of supporting their father,” we don’t “see how or why they get to this place.” She continues, “I think it’s really important to see the behind the scenes on why these people are where they are and where they stand. It’s fascinating.” The actress also teases that Margaret’s belief about her father does waver as the series progresses.

Odessa Young, who plays Margaret’s sister Martha, points out that the series digs deeper into the impact of the family than we’ve seen in previous tellings of the story (multiple documentaries exist about the case, including the other Staircase, released in 2004). She also details how Martha reacts to the case, which includes panic attacks in the courtroom, and what that tells the viewer about her.

“I think what I like so much about this series is that it’s not so focused on whether or not Michael is guilty or innocent. It’s understood that to a certain extent we’ll never know,” Young says.

Watch our interview with Turner and Young above for more.

The Staircase, New Episodes, Thursdays, HBO Max