Danish submarine inventor Peter Madsen, who was found guilty of the torture, sexual assault, murder and dismemberment of a Swedish reporter, appeared before an appeals court Wednesday to fight against his life sentence.

The three-day session at the Eastern High Court in Copenhagen will not deal with the April 25 guilty ruling. Madsen still denies murdering Kim Wall but wants to move on, according to his lawyer, so has accepted the verdict.

In Denmark, life is on average 16 years, but it can be extended if necessary.

Madsen, who claims Wall died accidentally inside the submarine in August 2017, wants a time-limited sentence, not an open-ended term. He has confessed to throwing her body parts into the Baltic Sea.

Wearing a dark blazer, a black T-shirt and jeans, Madsen listened quietly as prosecutor Kristian Kirk read out the April verdict to present the case.

The Copenhagen City Court had ruled unanimously that Madsen, 47, had lured Wall, 30, onto his home-made submarine on Aug. 10 with the promise of an interview.

The court ruled the murder was sexually motivated and premeditated, with the prosecution using Madsen's shifting explanations against him and quoting a court-ordered psychiatric report that described him as "emotionally impaired with severe lack of empathy, anger and guilt" and having "psychopathic tendencies."

Madsen's lawyer Betina Hald Engmark, on Wednesday said the prosecution case was based "on undocumented claims."

Clearly, she said, Madsen did something "horrible" by cutting Wall into pieces, but he should only be sentenced for that, noting that the cause of death has never been established. Under Danish law, indecent handling of a corpse carries a maximum sentence of six months in jail.