It began in 1993. A series of crimes occurred in Germany, several of them violent, including six murders. Police were at a loss to identify a suspect, but thanks to DNA evidence collected in connection with the crime scenes they were certain about a few things:

– the primary suspect was a woman;
– she was prolific, her DNA placing her at 40 crime scenes covering a wide geographic area;
– she was a skillful organizer, with apprehended accomplices from several counties; what is more, she commanded such loyalty from them that none would reveal her identity; and
– she was an expert at not getting caught.

Not only was she never arrested, but she had an uncanny way of avoiding being clearly seen by witnesses (some of whom identified her as male) or having her image captured on camera.

Her one-woman crime wave went on for 16 years. Police spent large sums of money and invested thousands of overtime man hours to no avail; their frustrated nickname for her became, “The woman without a face,” or more notoriously, “The Phantom of Heilbronn.”

It took until 2009 before law enforcement finally learned the secret to her anonymity: she didn’t exist.

As things turned out, the mysterious source of the crime scene DNA was probably a worker at a factory that made cotton swabs used in evidence collection kits. She apparently handled the swabs with her hands, transferring some of her skin cells to them. When the swabs were tested for the presence of DNA, the test results kept pointing to the factory worker who, not having actually committed any crimes, never showed up in any DNA database.

The case of “The Phantom of Heilbronn” may seem almost comical in hindsight. But it illustrates a possible problem with DNA evidence known as DNA transfer or “touch DNA.” And it was not the only time that DNA evidence has pointed to the wrong person.

More recently, DNA evidence seemed to implicate a homeless man in the 2012 murder of Raveesh Kumra, a wealthy entrepreneur in California’s Silicon Valley. What saved him from being charged with a crime he didn’t commit was the fact that he was comatose and hospitalized at the time of the murder, which forced the police to take another look at the supposedly incriminating DNA sample. When they did, they discovered that paramedics who had treated the homeless man were later the same day present at the murder scene, and that led to the DNA cross-contamination.

Other better-known cases that have raised at least the possibility of DNA sample contamination, by touch DNA or otherwise, include the Amanda Knox murder trial in Italy and the still-unsolved JonBenet Ramsey murder in Colorado.

How often does DNA transfer point police and prosecutors in the wrong direction? It may not happen frequently, but if it isn’t caught the result can be disastrous for everyone except the real culprit of the crime. This is one of the reasons that the Hunsucker Legal Group attorneys look at each and every step of the process when dealing with evidence. The science is only as good as the person performing the analysis and the steps taken to avoid cross contamination.