How groundbreaking voice analysis solved a 27-year-old kidnapping case
Ten-year-old Ursula Maria Herrmann disappeared on September 15, 1981, around 3:15 PM from her family's garden in the small Bavarian town of Eching, north of Munich. She was locked inside a homemade underground chamber measuring just 1.2 x 1.2 x 1.5 meters and suffocated, presumably from oxygen deprivation. It took 27 years before groundbreaking voice technology led to the conviction of postal worker Werner Mazurek—a milestone in German criminal history.
On that September day in 1981, Ursula was playing in the garden at her family's home in the quiet residential neighborhood. Suddenly, she was gone. Shortly after, police received a cassette tape from the kidnapper demanding two million Deutsche Marks in ransom. The family and police followed the instructions, but the little girl was never found.
Almost three years later, on August 30, 1984, people walking in the forest near Eching stumbled upon a strange wooden shed buried in the ground. Inside the primitive prison lay Ursula's body. The construction was simple but effective: She had no chance of escape and had suffocated in the darkness. The investigation hit a dead end. For over two decades, the case remained unsolved and became one of Germany's most notorious cold cases.
Kidnapping
Ursula Herrmann disappears from her garden in Eching
Body discovered
Ursula's body is found in a buried underground chamber
Confession
Werner Mazurek confesses to the crime after new evidence emerges
Verdict
Augsburg court sentences Mazurek to life imprisonment
Final verdict
Supreme court rejects appeal, verdict becomes final
The breakthrough came in April 2007. Werner Heinz Mazurek, born in 1949 and employed as a postal worker in Eching, suddenly confessed to the crime. But what had exposed him after a quarter century?
The answer lay in modern technology. As early as 1981, criminal investigators had attempted to analyze the voice on the ransom tape—without results. In 2007, investigators used BATVOX, an advanced acoustic analysis system. The result was clear: The voice on the tape matched Werner Mazurek's voice with over 99 percent probability.
It was the first time in Germany that voice analysis was accepted as legally valid evidence—a groundbreaking moment for forensic science. "The forensic examinations, especially the voice analysis, played a key role and set new standards," the chief prosecutor explained at sentencing.
Beyond voice analysis, wood comparisons also provided crucial evidence. The boards from the underground chamber were compared with wood from Mazurek's garage. The results were unambiguous: The machine processing was identical, as were the resin samples. It was spruce construction wood from the Eching area—and the boards undoubtedly came from Mazurek's possession.
The court in Augsburg convicted Werner Mazurek on November 28, 2008, of kidnapping with intent to kill, murder, and weapons violations, sentencing him to life imprisonment. The verdict became final in 2009 after Germany's supreme court rejected the appeal.
For the Herrmann family, the verdict after 27 years finally brought certainty. "After 27 years, we have certainty. The perpetrator was a neighbor," father Hermann Herrmann said the day after the verdict. The irony was particularly bitter: As a postal worker, Mazurek had regularly delivered mail to the Herrmann family and was known to the parents.
Mazurek's wife Irmgard M. was acquitted in 2010. Complicity in the crime could not be proven. According to her own statements, she knew nothing of her husband's plans.
The Ursula Herrmann case has significantly changed German criminal technology. The successful use of voice analysis opened new possibilities for solving both old and new crimes. The German Federal Criminal Police Office documented the case in 2008 as a milestone in forensic work.
Today, acoustic analyses and microscopic material comparisons are standard in investigations. The case demonstrates that even decades-old evidence can suddenly become strong proof through new technology—a hope for families of unsolved crimes around the world.
The case remains a shocking example of the cruelty of child kidnappings and simultaneously proof that justice sometimes requires patience—but can ultimately prevail.