WHEN a seven-year-old boy trod on a heroin syringe discarded in a playground, his parents insisted that the police open an investigation in the sleepy German spa town of Gerolstein.
Detectives examined the syringe for DNA traces and deposited the information in a central data bank. That was six years ago and no one expected anything to come of it.
Yet now the addict's genetic fingerprint has become an essential piece of a puzzle that, if solved, could trap a serial killer. The police this week intensified their search for a woman, dubbed the Phantom of Heilbronn, who they believe took part in the coldblooded murder of a woman police officer and the maiming of a male colleague at the end of April. Traces of her DNA, identical with that found on the syringe and dozens of other crime scenes, were found in the patrol car where the two officers were shot from behind.
For 14 years this spectral figure has been killing and burgling houses across southern Germany, France and Austria. Her identity has been a mystery, baffling detectives who can see no motive for the three murders committed so far. In charge of hunting the Phantom is Juergen Brauer (50), a state prosecutor who has been puzzled by the woman since she began her crime spree in 1993. Then, her DNA was found on the rim of a floral-printed tea cup at the home of Lieselotte Schlenger (62). She had been killed with wire used to bind bouquets of flowers.
When the DNA from the murder of the police officer in Heilbronn was matched to that found in Mrs Schlenger's apartment, Mr Brauer was stunned: "I just couldn't believe that the same woman could be capable of these two crimes."
The Phantom's genetic fingerprint was found at the scene of a third murder - the strangling of an antiques dealer, Jozef Walzenbach (61), in Freiburg in 2001. (© The Times, London)