Wonder, Obsession, and Murder in the World of Amateur Submarines,” Matthew Gavin Frank dives into the subculture of DIY ...

(FILES) This file photo taken on August 12, 2017 shows allegedly Swedish journalist Kim Wall standing in the tower of the private submarine "UC3 Nautilus" on August 11, 2017 in Copenhagen Harbor.

On Aug. 10, 2017, Wall boarded Madsen’s 33-ton, nearly 18-meter-long (60-foot-long) UC3 Nautilus submarine in Copenhagen. Eleven days later, her dismembered torso was found at sea off Copenhagen.

The Danish entrepreneur had built three submarines, including the UC3 Nautilus. He was in the process of building a homemade rocket that would launch him into space.

Madsen was convicted of the brutal murder of journalist Kim Wall onboard his homemade submarine, UC3 Nautilus, after she boarded it to interview him on 10 August 2017.

Kim Wall was killed by Peter Madsen after being invited aboard his UC3 Nautilus submarine for an interview. Facebook He threatened a prison psychologist and an officer with an imitation pistol ...

His third vessel, the UC3 Nautilus mini submarine, had been an even greater success. It had served as inspiration for Ubisoft’s video game Silent Hunter 5 and had been used on several missions.

The UC3 Nautilus was his third homemade submarine. In 2014, he created the Rocket Madsen Space Lab with the goal of developing a crewed spacecraft.

What followed was a series of ever-changing stories from Madsen about what happened after new details emerged about what happened on the Nautilus. He changed his story from saying she left the ...

In this Sunday, Aug. 13, 2017 file photo, police technicians board Peter Madsen’s submarine UC3 Nautilus on a pier in Copenhagen harbour, Denmark.