Free The Final Word by Liza Marklund

when an elderly woman had been strangled in her home after a burglary.
    In the winter of 2009 the German police devoted almost sixteen thousand hours of overtime to the search for the Phantom of Heilbronn: the investigating team was expanded, they conducted daily DNA analysis, tested seven hundred women, worked through almost three and a half thousand possible leads, and announced a €300,000 reward. All to no avail.
    Then, in March 2009, the case had taken a different turn. The French police conducted a DNA test on the charred remains of a male asylum-seeker, and discovered that he was in fact a woman, and not just any woman but the Phantom of Heilbronn. Among her many other crimes, she had murdered a police officer in Heilbronn two years before. At this point it had dawned on the detectives that something was seriously wrong with the DNA evidence.
    It turned out that the DNA from the forty different cases had not come from evidence gathered at the different crime scenes but from the cotton-wool swabs used to take the samples. All the swabs had come from the same factory in Eastern Europe.
    ‘Could there be some other explanation?’ Nina said. ‘Could the sample be right but the match wrong? Could the DNA actually belong to someone else?’
    ‘That’s a theoretical possibility,’ Johansson said.
    ‘But who, then? As far as we know, Berglund doesn’t have any sons, does he?’
    ‘Correct,’ Johansson said. ‘He’s never made any maintenance payments, either officially or unofficially, and he’s never been the subject of any paternity claims. Mind you, that isn’t proof that he doesn’t have a son . . .’
    Nina clasped her hands. ‘It still doesn’t make sense,’ she said. ‘Not for the Orminge case, and not for Djursholm. Even if he had a son, his DNA wouldn’t be such a good match, and mitochondrial DNA is passed down the maternal line.’
    They sank into silence as Nina read the report. Both of Ivar Berglund’s parents were dead – they had drowned in the early 1970s. His brother, Arne Berglund, had died in a car crash in the south of Spain twenty years ago.
    ‘Lots of accidental deaths in that family,’ Johansson said gloomily. ‘And it can hardly be his sister.’ Ivar Berglund’s younger sister, Ingela, lived in a care-home up in Luleå.
    Nina stared out of the window at the far side of the room. She could almost feel the heat hitting the glass. ‘Has anyone spoken to her?’
    ‘She has learning difficulties.’
    ‘But how bad are they? Do we know what sort of problems she’s got?’
    Johansson flicked through the file. ‘It doesn’t say. Presumably our colleagues decided it wouldn’t be useful. Maybe she can’t talk or perhaps they just wanted to spare her. It’s possible she doesn’t even know that her brother has been charged with murder.’
    Nina got to her feet. ‘Thanks for letting me take up your time,’ she said. ‘When are you next due to contact our European colleagues about the remaining cases?’
    Johansson sighed again.
    Nina left the room and saw Commissioner Q, head of the Criminal Intelligence Unit, disappear into his office at the end of the corridor. She hurried after him and knocked on his door. ‘Sorry,’ she said, ‘but have you got a moment?’
    Commissioner Q was holding a stained coffee mug. The buttons of his Hawaiian shirt had been done up wrongly. ‘Of course I have, Nina. What can I do for you?’
    Q was a very unusual sort of police chief, not just in his unorthodox style of dress and appalling taste in music (he loved the Eurovision Song Contest), but more particularly in his way of thinking, and the lack of presumption with which he approached things he didn’t understand. During the year she had been working for him at National Crime she had come to appreciate his acerbic way of communicating and open leadership style.
    ‘I’d like to go up to Luleå, to talk to Ivar Berglund’s sister.’
    The commissioner sat down behind his chaotic desk