Yes it does, good reading skills. That's the point. Human incompetency, related to DNA forensics. I didn't outright say that, though; the idea was that I would

Yes it does, good reading skills. That's the point. Human incompetency, related to DNA forensics. I didn't outright say that, though; the idea was that I would prepare you for a story of a serial killer so well concealed that her existence could only be inferred from trace DNA, but THEN there's the surprise twist - there is no serial killer, it's a trick of human incompetency. BOOM! The twist has a much greater effect because I didn't give it away at the start, but the twist also ties back in to my original statement about human incompetency - but NOT where you may have been expecting, and subverted expectations are a key part of surprise twists - and the story is also about DNA forensics. That's the previous subject again, the reader having been led around in an interesting and surprising circle.