A Copenhagen court on Wednesday found Danish inventor Peter Madsen guilty of the premeditated murder and sexual assault of Swedish journalist KimWall on his homemade submarine past year, handing him a life sentence.
Madsen's defense lawyer has said he should only be sentenced for cutting Wall into pieces.
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.
Wall, a 30-year-old freelance journalist who wrote for The New York Times, The Guardian and other publications, set out on the submarine on August 10 to interview Madsen, the co-founder of a company that develops and builds manned spacecraft.
In his final arguments on Monday, prosecutor Jakob Buch-Jepsen argued that Madsen had tortured and then murdered Wall to fulfill his violent sexual fantasies, in a case "so bad and disgusting that you as a prosecutor have no words to describe it".
In court he admitted, however, dismembering her body in order to lift it out of the vessel's hatch.
Madsen's lawyer said he would appeal.
A post-mortem examination of Ms Wall's remains revealed that she had been stabbed multiple times in the genitals.
He was charged with murder, dismemberment and indecent handling of a corpse.
Wall was a freelance journalist who had reported on topics such as tourism in post-earthquake Haiti and nuclear testing in the Marshall Islands and split her time between NY and China.
Wall's parents were not present for the verdict, but prosecutor Jakob Buch-Jepsen said he had spoken with other family members who were in court.
Investigators found Wall's DNA on Madsen's body, including cuts on his face and neck.
Madsen stood quietly listening as the judge read out the verdict.
Kim Wall was a freelance journalist with her work having already been published in The Guardian, The New York Times, Vice and Time Magazine.
When Madsen confessed to Wall's killing, he told investigators that after the journalist was dead he navigated the submarine in the Baltic Sea and slept with her body on board the vessel. The prosecution also examined the option of premises Madsen in a closed psychiatric clinic. The following day, the submarine sank due to what Madsen alleges were "technical difficulties" and he was rescued from a bay off Copenhagen - without Wall.
Her boyfriend raised the alarm the next day when she did not return from the trip.
"What do you do when you have a large problem?"
Madsen has said the reporter's death was accidental.
Earlier, the Danish inventor said in a statement that Wall died because of carbon monoxide poisoning aboard the submarine.