For 16 years German police chased a woman whose DNA tied together murders, robberies and burglaries across three countries. In 2009 they found the culprit: the cotton swabs in their own evidence kits.
Also called the Woman Without a Face: a presumed female serial killer inferred from DNA found at crime scenes in Germany, Austria and France from 1993 to 2009.
The March 2009 report where investigators first admit the Phantom's DNA may have come from the swabs used to collect it, not from any suspect.
A clear, full walkthrough of how a single ghost DNA profile tied together six murders and dozens of lesser crimes for over a decade.
In 2007 a young police officer was shot dead in Heilbronn. The Phantom's DNA on her car turned a bizarre puzzle into a nationwide manhunt.
The forensic post-mortem: sterile swabs are not DNA-free, and a worker at the factory had left her own DNA on thousands of them.
The full story, including the clue that broke it: the Phantom's DNA turning up on a male asylum seeker's paperwork, where no woman had been.
Why the case led to ISO 18385, a global standard for DNA-free forensic kits, and what it taught labs about trusting their own tools.