Into the Deep: The Submarine Murder Case (2020) on Netflix

Plot summary

In 2016, a filmmaker began filming Peter Madsen, an amateur inventor who was building a homemade submarine. A year into the project, Swedish freelance journalist Kim Wall boarded the vessel and disappeared. Madsen's accounts of what had happened to her changed with each telling. The film uses footage from his lab in the period leading up to that trip, along with interviews with members of his team. It premiered at the Sundance Film Festival. Before its release, some participants said they had not consented to appear, and the film was re-edited to remove those who did not wish to be in it.