The Allure of the Unknown

Brain City Berlin

People like Hilja Hoevenberg are usually only known from crime series: As an "Expert in Personal Identification and Facial Soft Tissue Reconstruction" at the Kriminaltechnisches Institut (Forensic Science Institute, KTI) of the Landeskriminalamt Berlin (Berlin Criminal Police Office, LKA), she conducts research in a field that anthropology and anatomy had long abandoned: she reconstructs the faces of unknown victims. In close collaboration with the Institute of Anatomy at Charité – Universitätsmedizin Berlin, her work supports not only investigating colleagues but also the victims' relatives.

In November 1988, the half-skeletonized body of a woman was found in the Spandau municipal forest. She lay in a pit that had apparently been disturbed by animals. The body was wrapped in a burlap sack, with two short plastic cords around the neck. The woman had clearly been murdered. How and why she died remains unclear to this day. So does her identity. The Bundeskriminalamt (Federal Criminal Police Office) continues to search for clues: On the website of the international investigation campaign "Identify Me," she is listed as one of 45 unidentified women who were murdered or died under unexplained circumstances. A reconstructed portrait of the Spandau victim is also shown there, accompanied by the note: "A facial soft tissue reconstruction was modeled onto the skull."

In 2025, this "cold case" was reopened. The responsible homicide division requested new examinations from the Kriminaltechnisches Institut of the Landeskriminalamt Berlin, including a new facial reconstruction based on findings from the research project "Correlations between Bone Structures and Soft Tissue in the Head/Neck Region." Hilja Hoevenberg oversees the project at the KTI. Straight blonde hair, black T-shirt, an unadorned face: the "Expert in Personal Identification and Facial Soft Tissue Reconstruction" appears open and highly committed: "Personal identification involves both victims and perpetrators. I compare morphological features using image data to identify individuals," she explains. Hilja Hoevenberg is one of around 470 employees at Germany’s largest forensic science institute. Scientists from fields such as physics, chemistry, biology, biochemistry, psychology, and linguistics support their colleagues in crime scene work and evidence collection. They also conduct interdisciplinary research projects together with technical specialists to develop new solutions and methods for solving and preventing crimes. Their work is internationally networked with authorities, universities, and non-university research institutions. Through her project, Hilja Hoevenberg is affiliated as a guest researcher with the Institute of Functional Anatomy at Charité – Universitätsmedizin Berlin, thereby entering a research niche long abandoned by the academic community

Bach and Neanderthals – Early Attempts That Flopped

"The idea of reconstructing soft tissues based on skeletal remains dates back to Georges Cuvier, co-founder of zoology and comparative anatomy. As early as the first half of the 19th century, he proposed supplementing incomplete fossil skeletons and deriving and modeling the associated muscles from bone structures to gain an impression of the type of a particular fossil species," explains Hoevenberg. Cuvier’s idea was taken up by others after 1850. The problem at the time: researchers used metric procedures based on numerical methods and combined the measurements with statistical data analysis techniques. This led to the creation of "typical individual measurements" of various body parts, from which "racial types" or "gender types" were determined based on body surfaces and bones. These average values were also used to identify individuals.

A fascinating example: In 1894, the city of Leipzig commissioned anatomist Wilhelm His to identify the skeleton of a man discovered during expansion work at the Johanniskirche. It was suspected that the remains might belong to composer Johann Sebastian Bach. His prepared a bone report and compared the skull with portrait paintings of Bach, which had only been created after the composer’s death. Based on this, sculptor Carl Ludwig Seffner created a "reproduction of Bach’s features over the skull cast," referencing calculated average values from soft tissue thickness measurements taken from eight healthy elderly male corpses. According to His, the result surpassed "each of the individual portraits in vitality and expressive character" – but it was more of an artistic creation than a scientific reconstruction of the composer’s head. Nevertheless, a review commission concluded from the result that the remains were very likely those of Johann Sebastian Bach.

A similar case involved the "Neanderthal from La Chapelle-aux-Saints": At the beginning of the 20th century, scientists from around the world attempted to reconstruct the face of the prehistoric human based on his fragmented skull, found in France in 1908. The results varied widely. This prompted German anatomist Heinrich von Eggeling to examine the accuracy of facial reconstruction using average soft tissue values. Like many of his scientific contemporaries, von Eggeling ultimately concluded that only the anthropological type could be reconstructed from the skull – not individual facial features. "Around 1930, the door to research on facial soft tissue reconstruction was essentially closed," says Hoevenberg. "The numerical method using average values had proven unsuccessful for reconstructing individual faces."

Back in the Spotlight with Hollywood

The topic lay dormant for a long time. It wasn’t until the release of the U.S. thriller Gorky Park in 1983 that facial reconstruction returned to public attention, sparking renewed interest. In the film, three corpses with disfigured faces are identified through scientific reconstruction. In 1993, Russian anthropologist Natalia Lebedinskaya outlined two unresolved methodological core issues in her Principles of Facial Reconstruction: the correlation between soft tissue and bone structures, and binding rules for determining facial form.

This is precisely where Hilja Hoevenberg’s research begins. Her current project at the KTI was initiated by a real case: “In 2003, a body was found in the harbor of Wittenberge. It could not be identified. My colleagues asked whether I could somehow reconstruct the face. I began with an extensive literature review and then contacted the Institute of Anatomy at Charité to ask whether collaboration within the framework of a master’s thesis would be possible. The then-director, Prof. Dr. Robert Nitsch, was very supportive and enabled me to work systematically on donor bodies. This eventually led to the current research project.”

For four years, Hilja Hoevenberg conducted dissections and searched for correlations between bone structures and soft tissue. Charité gave her the opportunity to attend dissection courses and all lectures relevant to the medical licensing examination. From there, she moved on to formulating rules for determining facial form. “These rules were tested in blind trials and initially not confirmed. I’ve learned to be resilient in the face of disappointment,” she recalls. One of the first key findings of her research: “If you want to reconstruct the head and neck region in a way that represents an individual face, it’s essential to replicate the entire ‘blueprint’ in its individual components. These should then be assembled piece by piece.”

Meticulous Attention to Detail

In her reconstruction work, Hilja Hoevenberg pays close attention to thoroughly examining everything found on and with the body. “As soon as forensic medicine has determined the cause of death, I begin the dissection. I look for morphological information, take notes, and photograph,” she explains. Once the soft tissue has been removed (macerated) from the skull, the reconstruction is built up piece by piece: muscle by muscle, cartilage by cartilage. Fat layers are then applied, followed by the skin. Hoevenberg: “This is modeling compound with tactile properties similar to human skin. The muscles are shaped from wax.” In this phase of her work, the native Dutch woman benefits greatly from her earlier studies in sculpture and painting. “Tactile shape information is also important for human perception: whether something feels soft or hard, appears glossy or matte, rough or smooth. I try to incorporate this into my work as much as possible.” Depending on the case, Hilja Hoevenberg collaborates with dentists or other medical specialists to assess the body for reconstruction.

With her research, Hilja Hoevenberg is a pioneer. Her work not only supports police investigators, but could also be of interest to transplant medicine. She hopes to advance the field further through scientific collective intelligence. Her conclusion: “Interdisciplinary exchange is crucial for research in the field of facial reconstruction.”

Author: Ernestine von der Osten-Sacken

© Ernestine von der Osten-Sacken
Hilja Hoevenberg is conducting research in a field that anthropology and anatomy have long since dismissed.
© Ernestine von der Osten-Sacken
His tasks include analysing traces of gunpowder, paint and break-ins. He also helps uncover forged paintings: Dr Paul Kuhlich heads the Chemistry/Physics Department at KTI.
© Ernestine von der Osten-Sacken
This multispectral camera allows them to visualise substances that are invisible to the naked eye. For example, traces of blood, semen or paint remnants.