What was so weird about the case was that she was not only a killer, but also a petty thief. She committed crimes all over Germany. And criminals who had also been at the scene denied knowing anything about her.
The answer was all in the Q-Tips used to take DNA samples. The same woman - presumably who worked at the Q-Tip factory - had packaged all the Q-Tips used in these cases, contaminated them with miniscule amounts of her DNA.
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