Anyone familiar with the mysterious death of Kathleen Peterson knows that we may never know what really happened. Her husband, Michael, was ultimately convicted of her murder, though he would be granted a new trial after eight years in prison. This twisting case is chronicled in Jean-Xavier de Lestrade’s 2004 docuseries The Staircase, which focuses mainly on the accused man’s protracted legal battles. Lestrade asks us to decide whether Kathleen’s death was a crime or an accident while ignoring a popular conspiracy theory.  

Many believe that rather than...