The prosecutor in the trial of Peter Madsen, who is accused of killing Kim Wall, 30, during a private submarine trip in August, also said there is a risk he could commit the same kind of crime again.
Jakob Buch-Jepsen said the victim, whose dismembered body was found in the sea, may have been tied with her own stockings before being killed.
He also spoke of straps found on Ms Wall’s body parts, in Madsen’s workshop and in his submarine, and argued marks on her wrists and ankles showed she was strapped to pipes inside the vessel.
He told Copenhagen City Court that Madsen, 47, should be given a life sentence, which is usually an average of 16 years in Denmark.
However, should Madsen receive a sentence of 16 years or less, Mr Buch-Jepsen called for the defendant to be placed in “forvaring”, or safe custody – a sentence with no definite time limit.
He said Madsen, who is accused of either cutting Ms Wall’s throat or strangling her, was not insane but “emotionally impaired with severe lack of empathy, anger and guilt”.
“It is uncertain whether Peter Madsen murdered Kim Wall by strangulation or cutting of the throat, but there is nothing that sows doubt about whether he killed Kim Wall on purpose,” he said.
“There is no doubt that he murdered Kim Wall on purpose and that he had a sexual motive.”
The prosecutor also quoted a court-ordered psychiatric report, which described the defendant being intelligent and as someone “with psychopathic tendencies”.
Betina Hald Engmark, defending, called the case a “horror story”, but said the prosecution details presented were “not based on facts”.
“It is not my client’s duty to prove that he is innocent. It is the task of the prosecutor to prove that he is guilty,” she told the court.
Ms Hald Engmark said there was no doubt Madsen had dismembered Ms Wall’s body but said there was a lack of evidence proving he killed her.
The inventor claims Ms Wall’s death was accidental following a pressure problem in his homemade submarine. The prosecution has said forensic experts “found nothing” to support the claim.
Madsen previously admitted to cutting up Ms Wall’s body before he “buried her at sea”, claiming he could not lift her up the submarine tower in one piece.
Her body was found weeks later contained in plastic bags on the Baltic Sea bed, with her body stabbed multiple times. Her cause of death has not been established.
Bringing Monday’s hearing to a close, the judge asked Madsen if he had any last words – to which he replied: “I’m very, very sorry.”
A verdict is expected to be returned on Wednesday.