In 2001, in the city of Durham, N.C., Michael Peterson, a writer and sometime political candidate, either did or did not kill his wife, Kathleen, who either fell down a flight of stairs or was beaten to death at its foot.

A French television crew, under the direction of Jean-Xavier de Lestrade, arrived soon after Peterson was accused of murder and produced an eight-episode docuseries detailing the trial from preparation to verdict called "The Staircase." The Peabody Award winner was an early model for the twist-and-turn true-crime documentaries and podcasts that have come to clutter the cultural landscape. Subsequent episodes were added and the 13-episode complete set is available on Netflix.

This mystery has now been converted into an HBO Max miniseries, also titled "The Staircase," with Colin Firth as Michael and Toni Collette as Kathleen. Created by Antonio Campos ("The Devil All the Time"), who also directs several episodes, and Maggie Cohn ("American Crime Story"), it can be streamed anytime and is not the first such adaptation. A 2007 Lifetime movie, "The Staircase Murders," preceded it, to little acclaim.

There is the promise of going behind closed doors, into the unrevealed personal lives of Michael and Kathleen and their blended family of adult children — an empty promise, given that those bits are necessarily invented, but the promise that powers all docudramas. And, fair enough, there is a drama only such inventions can deliver, and it's executed well here. It's a pro job. But if you're interested in the facts behind the fact-based fiction, there is little new to learn.

Where de Lestrade's documentary concentrates on the judicial process at great length, with its brainstorming sessions, focus groups and roving bands of experts, Campos wants to fill in spaces his predecessor didn't explore, almost all surrounding the family. Campos adds tension into their relationships, on what authority I can't say. The kids (Sophie Turner, Odessa Young, Patrick Schwarzenegger, Dane DeHaan and Olivia DeJonge) don't always get along with one another or their parents; some of have problems of their own.

Despite the added tension, the series is made with a dedication to keeping things from getting too sensational, too declamatory, too actorish. The exposition is nicely integrated into the action.

Campos' version of "The Staircase" is a well researched work of the imagination, but straight documentary film also has its limitations. Even at eight hours, the original "Staircase" left out more than 500 hours of footage. Subjects, too, leave things out. They tell lies. They might play to the camera or be intimidated by it. And the camera isn't everywhere all the time.

The real strength of cinéma vérité may be that it inspires questions — questions about people, and how they are, and our own judgments — rather than delivering answers. (The original French title of "The Staircase" is "Soupçons" — "Suspicions.")

Finally, the ambiguities of the miniseries within the miniseries that the French crew is making here echoes the ambiguities of the adversarial justice system they're examining. "Twelve jurors declare one of the stories the winner, and that story becomes justice," says Juliette Binoche, playing a character the network has officially declared a spoiler, contemplating the question "What is justice?"

"Justice is a construct, little more than a game, a game that shapes the outcome of a man's life."