FILE - This April 30, 2008 file photo shows a submarine and its owner Peter Madsen. One of the most talked-about and macabre court cases in recent Danish history is set to conclude Wednesday, April 25, 2018 when the verdict is handed down on whether Peter Madsen tortured and murdered a Swedish journalist during a private submarine trip. (Niels Hougaard/Ritzau via AP, File)
FILE - This April 30, 2008 file photo shows a submarine and its owner Peter Madsen. One of the most talked-about and macabre court cases in recent Danish history is set to conclude Wednesday, April 25, 2018 when the verdict is handed down on whether Peter Madsen tortured and murdered a Swedish journalist during a private submarine trip. (Niels Hougaard/Ritzau via AP, File) Credit: Hougaard Niels

COPENHAGEN, Denmark — A self-taught Danish engineer was convicted of murder Wednesday for luring a Swedish journalist on to his homemade submarine, then torturing and killing her before dismembering her body and dumping it at sea in a sensational case that has gripped Scandinavia.

Peter Madsen, 47, was sentenced in Copenhagen City Court to life in prison for killing Kim Wall, a 30-year-old freelance reporter, after bringing her aboard his submarine with the promise of an interview last summer.

“We are talking about a cynical and planned sexual assault and brutal murder of a random woman, who in connection with her journalistic work had accepted an offer to go sailing in the defendant’s submarine,” presiding Judge Anette Burkoe told the court.

Life sentences in Denmark usually mean 16 years in prison, but convicts are reassessed during their incarceration to determine whether they would pose a danger to society if released and can be kept longer.

Prosecutor Jakob Buch-Jepsen said he was satisfied that Madsen got “the heaviest penalty in Danish law, namely prison for life.”

Wall was at a waterfront party with her Danish boyfriend on Aug. 10 when she received a text from Madsen that he would grant her the interview she had been waiting for months for if she joined him immediately. She was last seen waving goodbye to her friends from the bridge of the submarine as it sailed into the Baltic.

The submarine was spotted the next day as it passed a lighthouse in waters between Denmark and Sweden, then sank shortly afterward in what police later concluded was an intentional act.

After being rescued, Madsen told authorities that before the submarine went down he had dropped Wall off on Copenhagen’s trendy Refshale island, where she lived and he kept his workshop.

After further questioning, that story changed and Madsen claimed that Wall hit her head on the submarine’s hatch and died accidentally. He said he then buried her at sea.

Eleven days after her disappearance, a cyclist found Wall’s mutilated torso. Police divers then recovered a weighted-down bag containing her head, other body parts and clothing in October. When no injuries were found to her skull, Madsen changed his story again, saying that she died of carbon monoxide poisoning in a malfunction on the submarine.

Wall, he told the court, had “a wonderful evening until it ended in an accident.”

The specific cause of death was never established, but Buch-Jepsen introduced evidence that Madsen stashed a saw and sharpened screwdrivers on board the submarine, suggesting it was premediated murder.

Wall’s dismembered torso had multiple stabs wound, including in the genitals.