COPENHAGEN (Reuters) - (This October 3 story has been refiled to Corrects detention period to four weeks, not four months, in seventh paragraph.) 
 
 Peter Madsen, Danish inventor, engineer, rocket- and u-boat builder, talks about entrepreneurship during Danish Business Day event held in Copenhagen, Denmark, May 9, 2017. Scanpix Denmark/Ida Marie Odgaard/via REUTERS 
 
 A Danish inventor charged with murdering Swedish journalist Kim Wall in his home-made submarine had video footage on his computer showing women being violently killed, a court heard on Tuesday. 
 
 A police prosecutor said officers found images “which we presume to be real” of women being strangled and decapitated on the hard drive on Peter Madsen’s computer in a laboratory he ran. 
 
 That, together with new post-mortem evidence showing Wall was stabbed in her ribcage and genitals “around or shortly after her death,” was adding to the case against Madsen, the prosecutor, Jakob Buch-Jepsen, told the Copenhagen court. 
 
 DNA tests from Madsen’s nails, face and neck showed a clear match with Wall’s, Buch-Jepsen said, though the exact cause of death remained unknown. “Our suspicion hasn’t changed, it has been strengthened since (the last hearing on) September 5,” he added. 
 
 Madsen, who denies murdering Wall and another charge of mutilating her body, appeared in court via video link dressed in a green boilersuit. 
 
 He said the computer searched by police was not his. “They are the space laboratory’s tools which have been used by everyone in the laboratory,” he said. The court heard he had been working on building a space rocket in the lab. 
 
 He remained calm during the pre-trial session, sitting with his hands folded most of the time. The court ordered him detained for another four weeks as investigations continued. 
 
 Wall, a 30-year-old freelance journalist who was researching a story on Madsen, went missing after he took her out to sea in the 17-metre (56-foot) craft in August. 
 
 Madsen has told the court in past hearings Wall died accidentally, saying she was hit by a heavy hatch cover on his UC3 Nautilus submarine. 
 
 On August 23, police identified a headless female torso washed ashore in Copenhagen as Wall’s. 
 
 Madsen has also denied amputating her limbs, saying he tried to bury her whole body at sea. ||||| Peter Madsen says account of journalist’s death changed because he wanted to spare her relatives ‘grim’ details 
 
 A Danish inventor has denied murdering the Swedish journalist Kim Wall on his homemade submarine, claiming that he had lied previously about how she died only to spare her relatives. 
 
 “I deny that I am guilty of the murder of Kim Wall,” Peter Madsen told the court in Copenhagen on the first day of his trial, after prosecutor Jakob Buch-Jepsen had presented a barrage of new detail. 
 
 Madsen said he had claimed up until October that Wall had been killed by a heavy latch falling on her head to avoid making public the “grim” reality of her death. 
 
 “I was only thinking about Kim Wall’s relatives,” he said. “It’s a very, very horrible story. I knew she was dead and she would not come back. I had only one purpose and it was to spare the relatives as much as possible.” 
 
 About 120 journalists from 15 different countries crowded into the court and a media room at Copenhagen district court, reflecting the huge international interest in the case. 
 
 
 
 Wall, an award-winning journalist, joined Madsen on the afternoon of 10 August, hoping to interview him about his nine-year push to send himself into suborbital space. Her torso was spotted 11 days later off the coast of Copenhagen, and her head, arms and legs were found by police divers over the following months. 
 
 During his questioning in court, Madsen said a technical fault had led to exhaust gases being pumped into the submarine’s “mess”, poisoning Wall while he was trapped outside, the negative pressure preventing him from opening the hatch. 
 
 “I tried to shout to Kim that she should try to turn off the engines,” he said. “I do not know if Kim succeeded, but the engines stopped.” 
 
 That released the pressure, allowing him to open the hatch, he said, whereupon he found her lifeless body. 
 
 
 
 Buch-Jepsen thoroughly discounted Madsen’s story during his morning overview, when he said such an accident would have led to rapid heating, for which there was no evidence. A technical report will be presented later in the trial. 
 
 The trial opened with new forensic evidence, as the prosecution began presenting its case that Madsen killed Wall, 30, to fulfil his violent sexual fantasies, in an act planned days or even months beforehand. 
 
 Buch-Jepsen told the court that no traces of Madsen’s DNA had been found on the body of the Swedish journalist. “But traces of semen have been found in the underpants which were secured from Peter Madsen after the arrest,” he said. Under questioning, Madsen denied ejaculating while he was with Wall. 
 
 
 
 Madsen, 47, dressed in a black T-shirt, spent the morning calmly leafing through the prosecution’s papers, as Buch-Jepsen ran through evidence including photographs and diagrams of the stab wounds on Wall’s body. 
 
 Madsen’s denial of guilt on Thursday afternoon were his first words in court since police divers found Wall’s head in October, disproving his earlier claim that a heavy latch had smashed her skull. 
 
 In a detailed presentation that lasted about two and a half hours, Buch-Jepsen said flecks of Kim Wall’s blood had been found on Madsen’s nostrils, and fresh scratches on his underarms. 
 
 He said Madsen had, in the months leading up to Wall’s death, searched the internet for videos of women being beheaded. Police, he said, had managed to recreate Madsen’s iPhone from backups right up until the day of the submarine trip on 10 August. 
 
 Madsen had used it to carry out mobile searches for “throats”, “haircut”, “girl” and “pain”, with the last search made in the early morning before Wall joined him on his submarine. 
 
 Buch-Jepsen also showed the court pictures of Wall’s arms, saying a strap with a ratchet buckle found on the submarine matched marks on her wrists. 
 
 
 
 He showed pictures of Madsen’s workshop months before the event, pointing out a saw that he said police divers later found in Køge Bay, south of Copenhagen, close to the plastic bag holding Wall’s head. 
 
 An investigation by forensic psychiatrists had determined, he continued, that Madsen had “narcissistic and psychopathic traits” showing a “severe lack of empathy, remorse and guilt”, despite a “superficial charm”. 
 
 The trial will be held over 12 days in March and April, with the verdict expected on 25 April, but may be delayed if days are postponed due to a planned strike by public sector workers. ||||| Swedish journalist’s dismembered remains found at sea after she failed to return from trip on Madsen’s submarine 
 
 A Danish inventor has been sentenced to life in prison for the premeditated murder and sexual assault of the Swedish journalist Kim Wall on his submarine in August last year. 
 
 The judge, Anette Burkø, and two jurors found Peter Madsen, 47, guilty of all three of the main charges of premeditated murder, aggravated sexual assault and desecrating a corpse. 
 
 “This is a cynical and pre-planned sexual assault of a particularly brutal nature on a random woman who, in connection with her journalistic work, accepted an invitation for a sailing trip on the accused’s submarine,” Burkø said, explaining the rare decision to hand down Denmark’s most severe sentence. 
 
 Wall’s parents, Ingrid and Joachim Wall, who had followed much of the trial from the courtroom, were not present for the verdict, although the seven family seats were taken by other friends and relatives. 
 
 Wall was 30 when she died. The journalist had reported from all over the world for Time magazine, the New York Times and the Guardian, among others. Her boyfriend told the court she was “incredibly ambitious” and “amazingly curious”. 
 
 Madsen looked crushed as he heard the verdict, sitting motionless for close to a minute with his eyes closed and his head bowed, in contrast to his behaviour during the trial, when he had looked frequently around the courtroom. He then left to confer with his defence lawyer, Betina Hald Engmark, who announced on their return that he would appeal. 
 
 Facebook Twitter Pinterest Peter Madsen in front of his homemade submarine in Copenhagen, Denmark. Photograph: Mikko Suominen/Getty Images 
 
 The case has gripped Denmark ever since Wall failed to return from a trip on Madsen’s self-built Nautilus submarine on 10 August. Madsen was a semi-celebrity at the time of his arrest, having made a name for himself with three self-built submarines and two crowdfunded manned space projects. 
 
 
 
 Burkø said his version of events – that Wall died when an accident filled the vessel with toxic exhaust fumes – was “not credible and not consistent with the following decision to dismember the body”. Madsen had changed his explanation for Wall’s death several times, Burkø noted. 
 
 She said the court instead believed the prosecution’s theory that he had sexually tortured Wall to fulfil a violent sexual fantasy. 
 
 It is very unusual for a life sentence to be handed down for the murder of a single person in Denmark, where prisoners sentenced to life imprisonment serve an average of 16 years. 
 
 Madsen admitted to just one of the four charges, mistreatment of a corpse. He confessed in October to dismembering Wall’s body after divers found her head, legs and clothing in Køge Bay, claiming it had been necessary to cut it up in order to remove it from the submarine. 
 
 Facebook Twitter Pinterest Prosecutor Jakob Buch-Jepsen gives a media briefing after the verdict. Photograph: Scanpix Denmark/Reuters 
 
 Over the course of the 11-day trial, spread over seven weeks, prosecutors presented their case in often horrific detail. But Madsen himself refused to go into detail in court, calling Wall’s death “a very, very traumatic event which I do not want to describe”. 
 
 When he was arrested in August, Madsen initially claimed to have dropped Wall off on land, but he almost immediately admitted that she had died onboard and that he had then “buried her at sea”. 
 
 At first, he said her skull had been crushed by a heavy latch, but after the discovery of Wall’s head, he said she had been asphyxiated, claiming to have come up with his first story to spare Wall’s parents. 
 
 
 
 During the trial, the court heard from a woman to whom Madsen had confessed that he was “a psychopath, but a loving one”, a judgment backed up by a forensic psychiatric report that described Madsen as a “perverse polymorph” with “psychopathic traits”. 
 
 Such was the interest in the trial that the Copenhagen district court opened up a special room with a video link on some days to accommodate as many as 115 journalists from 15 countries. Wall’s parents attended the trial most days and quietly took notes from specially reserved seats beside the media section. 
 
 Madsen expressed his regret when asked to make a closing statement at the end of the trial. “The only thing I want to say is that I’m very, very sorry for what has happened,” he said. 
 
 Madsen was also ordered to pay damages to Wall’s boyfriend. 
 
 • This article was amended on 26 April 2018. An earlier version said Peter Madsen was found guilty of reckless sailing and ordered to pay damages to Wall’s parents.
– Life sentences are unusual in Denmark, even when the crime is murder, but that's what Danish inventor Peter Madsen was handed on Wednesday. Judge Anette Burkoe at the Copenhagen City Court said she and the two jurors—whose opinions all held equal weight in the case—found Swedish journalist Kim Wall was murdered, telling Madsen he hadn't given "a trustworthy" explanation for her death and that "there is clear evidence that the accused has shown an interest in killing and dismembering people." The 47-year-old stood quietly listening as the verdict was read, reports the AP, with the Guardian describing him as "visibly nervous." The paper notes life sentences in Denmark typically average 16 years; Madsen has two weeks to decide whether he will appeal. Madsen had maintained that he did not murder Wall, but did admit to cutting up her body and disposing of it in the sea after what he said was an accidental death. The New York Times reports prosecutor Jakob Buch-Jepsen had argued Madsen was fixated on murdering a woman after a rocket launch was scrapped on Aug. 8, two days before Wall died. Buch-Jepsen said Madsen texted three women an invitation to meet him on the sub but was turned down. Wall boarded the sub on Aug. 10 for an interview that she had tried to secure for months; Madsen had texted her that day with the invite. "It was random chance that it turned out to be Kim Wall," Buch-Jepsen said. Wall skipped her own going away party to head to the interview. More on that here.