Ludwig Tessnow was born on February 15, 1872, in Germany. Very little is known about his early life, and no extensive background records exist regarding his upbringing, education, or family relationships. He worked as a journeyman carpenter, which likely allowed him to move between towns and villages with ease, picking up various woodworking jobs along the way.

Tessnow was seen by his neighbors and clients as an ordinary laborer. He had a reputation for being quiet, often keeping to himself, and did not have any notable criminal history prior to the events that led to his arrest. There were no immediate signs of mental illness or erratic behavior during his interrogations in 1898, and he convincingly maintained a calm demeanor under suspicion.

Following his release in 1898 after being linked to the disappearance and murder of two girls, Tessnow relocated from Lechtingen to Baabe in Mecklenburg-Vorpommern in early 1899, perhaps to distance himself from suspicion or restart his life.

The first murders linked to Ludwig Tessnow occurred on September 9, 1898, in the village of Lechtingen, near Osnabrück. That morning, two seven-year-old girls, Hannelore Heidemann and Else Langemeier set off for school, just a few hundred yards from their homes. When they failed to return home for lunch, their parents raised the alarm, and a local search party was formed. After several hours, the nude and dismembered body of Heidemann was discovered in a nearby forest. Later that night, Else Langemeier’s mutilated corpse was also found, concealed in nearby bushes.

Both girls had been dismembered and subjected to horrific mutilation. Police discovered a button at the crime scene matching the type on Tessnow’s jacket, which was notably missing a button. One witness reported seeing Tessnow that morning, walking away from the forest with dark stains on his clothing. Tessnow was arrested and questioned, but calmly denied any involvement. He claimed the stains were from wood dye, a plausible excuse given his trade, and insisted he had lost the button weeks prior. Authorities lacked definitive evidence, and the case stalled. Tessnow was released.

In early 1899, Tessnow relocated to the village of Baabe in Rügen. For nearly three years, he remained undisturbed. Then, on the evening of July 1, 1901, two brothers, eight-year-old Hermann Stubbe and six-year-old Peter Stubbe went missing in the coastal resort of Göhren. The next morning, their bodies were found in a wooded area, bearing shockingly similar injuries to the girls murdered in 1898. The boys had been bludgeoned, dismembered, and mutilated, with several body parts scattered around the forest. Both had suffered massive trauma; Peter’s skull had been crushed, and his internal organs were exposed. The hearts of both children were missing.

Witness testimony soon linked Tessnow to the scene again, a local observed him speaking with the boys shortly before their disappearance. Police searched Tessnow’s home and found clothing and boots, still damp from being recently washed, stained with what appeared to be blood. Again, Tessnow insisted the stains were wood dye. However, this time, science caught up with him.

Prosecutor Ernst Hubschmann recalled a case from just three weeks earlier, in which seven sheep had been found grotesquely mutilated in a meadow, their limbs and entrails scattered similarly to the human victims. A farmer identified Tessnow as the man fleeing the scene, and the similarity in mutilation led to suspicions that the same person was responsible for both the animal and child killings.

Enter Paul Uhlenhuth, a biologist who had recently developed the precipitin test—a scientific method capable of distinguishing between human and animal blood. Uhlenhuth was commissioned to test Tessnow’s clothing and the stone used in the bludgeoning. His results were groundbreaking: the stains on Tessnow’s overalls, jacket, trousers, and boots contained both human and sheep blood. Some of the blood had even soaked through to the inner layers of the garments. This would become the first criminal case in history where a conviction was secured based on forensic blood testing.

Tessnow’s trial began in spring 1902 in Greifswald. He was charged with two counts of murder and one count of attempted murder. Despite his plea of innocence, the forensic evidence was overwhelming. Several psychiatric experts declared that Tessnow had committed the murders while in a state of degenerate moral responsibility, but the prosecution countered with its own experts who asserted he was sane enough to stand trial. After ten days, Tessnow was convicted on all counts and sentenced to death by beheading. He also received a two-year prison sentence for the assault and lost all of his political rights.

Tessnow’s appeal was rejected on March 14, 1904, by the Reichsgericht in Leipzig. It is believed that he was executed later that year by guillotine in the courtyard of Greifswald prison.