The Horrifying & Disturbing Case Of Ludwig Tessnow Killer Caught by the First Blood Test in History

Added: 2026-05-30

[00:00:08]Gust 1901. A biologist named Paul Ulenuth stands over a workbench arrayed with glass vials, pipets, and strips of fabric cut from a carpenter's clothing.

[00:00:19]The fabric is stained. Dark reddish brown blotches dried and set into the weave. The carpenter who wore these clothes insists the stains are wood dye.

[00:00:28]He has said this before. Three years ago in another town after another pair of children were found dead in the forest.

[00:00:35]He said exactly the same thing. And 3 years ago, science had no answer. The stains [music] could not be tested. The carpenter walked free, but the world has changed since then. In the months before this moment, Ulen Huth has perfected a procedure that can do what no human eye, no chemical reagent, no microscope has ever been able to do. determine whether a stain is blood and if so whether that blood came from a human being or from an animal. He applies his method. Over 100 individual stains are tested. The results are unambiguous. Some stains are wood dye, but the vast majority are blood, human blood, and several more are the blood of sheep. The carpenter's name is Levik Tessnau, and the stains on his clothing are about to become the most important piece of forensic evidence in the history of criminal science. Welcome to the Crimson Files. If you are new to this channel, consider subscribing and turning on notifications. The stories we tell here sit at the intersection of crime and science. Moments where the truth was hidden until someone found a way to make it visible. Join us to understand why the Tesno case was a turning point. You must first understand the problem it solved. By the end of the 19th century, forensic science had made real but frustratingly limited progress in the analysis of blood. Since 1853, when the anatomist Ludvik Tykeman discovered that hemoglobin could be converted into identifiable crystals when heated in acetic acid, investigators had possessed a reliable method for determining whether a stain was blood. Spectroscopic examination, passing light through a dissolved stain, and analyzing the absorption patterns, could confirm the presence of hemoglobin with considerable accuracy. The Guak reaction, a chemical test using tree resin and hydrogen peroxide, offered an additional tool. By 1890, a competent forensic examiner could say with confidence. This stain is blood. But that was where certainty ended. No test existed that could distinguish human blood from the blood of a pig, a cow, a sheep, or a horse. And in an age when butchers, farmers, tanners, and laborers of all kinds routinely came into contact with animal blood, this limitation was devastating. A suspect could simply claim the stains on his clothing came from slaughtering livestock, from handling raw meat, from a nosebleleed, from a workplace accident, and there was no scientific means of proving otherwise. The same limitation applied to other substances entirely. wood dye, certain vegetable stains, rust, and iron rich soil could all produce dark reddish brown discolorations that to the naked eye were indistinguishable from dried blood. A carpenter, a painter, a metal worker, any tradesman could offer a plausible alternative explanation for the marks on his clothes, and the forensic science of the era was powerless to contradict him. This was the gap that Ludvik Tessnau exploited, and it was the gap that Paul Olin Huth closed. Ludvik Tessna was born on the 15th of February 1872 in Prussia. Almost nothing is recorded of his early life, his family or his upbringing. What is known as his trade? He was a carpenter, a journeyman craftsman who moved between towns and villages in northern Germany, taking work where he could find it.

[00:04:03][music] He was described as reclusive, eccentric, and locally known as something of an oddity. He was not married. He had no known close associates. In the context of late 19th century Germany, a journeyman carpenter was an unremarkable figure. The tradition of itinerant craftsman, wandering tradesmen who moved from commission to commission was centuries old. Such men passed through villages, performed their work and moved on. They were part of the social fabric but not embedded within it. They were noticed but not closely observed. They were in the most practical sense invisible.

[00:04:40]Tesno used this invisibility [music] to devastating effect. On the morning of the 9th of September 1898, two 7-year-old girls, Hannah Hidman and Elsa Lungmeer, left their neighboring homes near the village of Lectingan, north of the town of Osnibbrook to walk to school. The schoolhouse was only 300 yards from Hannalor's Cottage. Neither child arrived. When both girls failed to return home for lunch at a quarter 12, their mothers visited the school and discovered that neither had been seen that morning. Their fathers were fetched from work. Friends and neighbors joined the search. The entire village was covered. After 3 hours, the search expanded into the surrounding woodland.

[00:05:26]Shortly after 9:00 that evening, the searchers found Hannalor Haidaman. She had been killed and extensively mutilated with portions of her body scattered across a wide area of the forest floor. Later that night, police discovered El Langmire concealed in nearby bushes. She had been subjected to the same treatment. The details of the injuries inflicted upon these children were recorded in the police files, but need not be reproduced here. What matters for the narrative is this. The manner of death was characterized by extreme and purposeful violence directed at the bodies after death. A pattern of mutilation and dismemberment that went far beyond what any rational motive could explain. Police questioning of local residents produced a witness who reported seeing a carpenter named Ludvig Tessnau walking into the village from the direction of the woodland on the morning of the children's disappearance.

[00:06:24]The witness stated that Tessnau's clothing was heavily stained with dark reddish brown blotches. Tessnau was arrested. He was still wearing the stained clothing. He was calm, composed, and entirely cooperative. He denied any involvement. The stains, he explained, were wood dye, a substance he used daily in his trade. Furthermore, a button found at the crime scene matched the buttons on his suit, which was missing one. Tesso claimed the button had been lost weeks earlier. The police were suspicious, but suspicion was not evidence. In 1898, no test existed that could prove the stains on Tessnau's clothing were blood rather than wood dye. Without that proof, there was no case. Tessno was released. He made no attempt to leave Lexingan. He was observed wearing the same stained clothing on several subsequent occasions. In January of 1899, he relocated to the village [music] of Baba on the island of Rugan off the Baltic coast of northern Germany. The murders of Hannalora Haidaman and El Langomire remained unsolved. If this story is holding your attention, take a moment to leave a comment or share this episode with someone who appreciates the history of science and justice. Every share helps these forgotten cases reach new ears. 2 and 1/2 years passed. On the evening of the 1st of July 1901, two young brothers, Herman Stub, age 8, and Peter Stub, age 6, left their home in the Baltic resort town of Guran on the island of Rugan to play near the family house. When the boys failed to return for supper, their father, several neighbors, and the village policemen searched the area. The boys were not found. They were reported missing. The following morning, a neighbor discovered the brother's bodies in a thicket of woodland close to their home. Both boys had been subjected to extreme violence.

[00:08:19]They had been bludgeoned with a large stone which was found nearby, stained and bloodied. Both had been mutilated and dismembered in a manner strikingly similar to the Lecting and murders. The skull of the younger boy, Peter, had been crushed. Sections of both bodies had been scattered across a wide area of the woodland. The heart of the older boy, Herman, was missing and was never recovered. Police questioned all residents in the area. One witness came forward to report that she had seen the brothers speaking with a journeyman carpenter named Ludvig Tessnau. On the afternoon of their disappearance, Tessna, she said, was a native of Rugan, a locally eccentric figure who lived in the neighboring village of Bab. Tessna was arrested and taken into custody on the 2nd of July 1901. He protested his innocence. A search of his home revealed several items of clothing that, although still damp from having been recently washed, bore dark stains. A heavily stained pair of boots was recovered from beneath a stone sink in his kitchen.

[00:09:25]These had also been washed. When questioned about the stains, Tessnau gave the same explanation he had given 3 years earlier. They were wood dye, a natural byproduct of his trade, nothing more. The local prosecutor, Ernst Hubesman, was not satisfied. He began to investigate Tessnell's recent movements and quickly uncovered a disturbing detail. Less than 3 weeks before the brother's murders, a local farmer had observed a young man fleeing from one of his meadows. When the farmer investigated, he discovered that seven of his sheep had been savagely mutilated, their limbs severed and viscera scattered across the field. The attack had initially been attributed to witchcraft rights, a superstition that still lingered in the rural communities of the Baltic coast. Hoopsman noted the unmistakable similarities between the manner in which the sheep had been mutilated and the condition of the stubby brother's bodies. He arranged for the farmer to view a lineup of possible suspects. The farmer identified Tessno without hesitation as the man he had seen running from his field. Tessno admitted that he had read newspaper reports about the sheep mutilation. He denied involvement and once again he insisted that the stains on his clothing were wood dye, not blood. The examining magistrate assigned to the case, Johan Klaus Schmidt, reviewed Tessnau's statements and noticed something that sent a chill through the investigation.

[00:10:55]The suspect's repeated insistence that stains on his clothing were would dye, not blood, echoed a detail from an unsolved case that Schmidt had read about. The 1898 murders of two young girls near Osnabbrook. Schmidt investigated further. He soon confirmed that the suspect in the Lectingan case had also been a carpenter named Ludvig Tessnau and that Tessnau had been released from custody in Osnibbrook because the stains on his clothing could not be proven to be blood. [music] The pattern was now unmistakable. Two double murders of children separated by 3 years and hundreds of kilome committed in identical fashion with the same suspect and the same defense. Its only would die. But Schmidt was also aware that in 1898 that defense had been unassailable.

[00:11:45]The question was whether anything had changed, whether science now possessed the tools to break through Tesnau's story. It had. Paul Ulenhuth was born on the 7th of January 1870 in Hanover. By 1901, he was an assistant at the hygiene institute of the University of Grisswald, the very city where Tessnell was being held for trial. Ulen Huth was a bacteriologist and immunologist whose research had been shaped by a discovery made in the 1890s by Emil vonbearing that animals inoculated with certain toxins developed defensive substances in their blood serum. These substances later called antibodies were specific to the foreign agent that had triggered their production. Building on this principle and on the work of Jules Boude, Ulan Huth had conducted a series of elegant experiments. In 1900, he injected protein from a chicken egg into a rabbit. Over successive injections, the rabbit's immune system produced antibodies specifically designed to attack chicken egg protein. When Ulen Huth then mixed serum drawn from the immunized rabbit with egg white, the egg protein separated from the liquid, forming a cloudy precipitate. The reaction was unmistakable and specific.

[00:13:03]The rabbit serum reacted only to chicken protein and to nothing else. Yulan Huth then extended the principle. He injected rabbits with human blood. The rabbits developed antibodies against human blood proteins. When serum from these immunized rabbits was mixed with a sample of human blood, even old, dried, dissolved human blood, the characteristic cloudy precipitate formed. When the same serum was mixed with animal blood, no reaction occurred.

[00:13:31]For the first time in the history of science, it was possible to take a dried stain of unknown origin, dissolve it, [music] and determine with certainty whether it was human blood. Ulan Huth's colleague at Grvald, Professor Otto Boomer, the university's forensic medicine expert and the city's coroner had helped refine the technique, extending its reliability to blood stains that were months or even years old. Prosecutor Hubman met with magistrate Schmidt. They discussed whether Ulen Houth should be commissioned to test the clothing recovered from Tessnau's home. The decision was approved on the 29th of July and the 1st of August 1901. Two packages containing Tessnau's clothing, footwear, and the bloodstained deals recovered from the crime scene were delivered Ulen Huth's laboratory. What followed was the most meticulous forensic examination that had ever been conducted on a suspect's clothing. Ulen Huth tested over 100 individual stains across Tessno's coat, trousers, waste coat, cap, vest, and boots. Each stain was carefully excised, dissolved, and subjected to the precipitant reaction.

[00:14:41]On the 5th of August 1901, Oolen Huth submitted his report. Some stains upon Tessnau's overalls were, as the carpenter had claimed, would die. The precipitant test confirmed this. The dissolved stains produced no reaction with any of the prepared antisera, but the vast majority of the stains told [music] a very different story. Human blood was identified in six locations upon Tessno's coat, seven locations upon his trousers, four locations upon his waist coat, and one location each upon his cap and vest. Several additional stains upon his jacket and trousers were identified as the blood of sheep. The bloodstained stone recovered from the crime scene was also tested. The discolorations upon it were confirmed as human blood. The carpenter's [music] defense, the defense that had protected him for 3 years, was destroyed in a laboratory by a rabbit's immune system and a cloudy precipitate in a glass vial. Ludvik Tesnau's trial for the murders of Herman and Peter Stubby was held in the spring of 1902 in Grisswald.

[00:15:46]He pleaded not guilty to two counts of murder and one count of murderous assault. The trial lasted 10 days. The chief prosecution witness was Paul Oolen Huth himself who [music] took the stand and methodically explained his findings.

[00:16:00]He described the precipitant test, its scientific basis, and the results of his analysis. He testified that contrary to Tessnau's insistence, the stains upon his clothing and boots were not would die. They were human blood and animal blood, identifiable and distinct. The wood dye was present as well, precisely where one would expect it on a working carpenter's garments, but it existed alongside blood stains that no amount of washing had been able to remove. The prosecution also presented the eyewitness who had seen Tessno speaking with the Stub brothers on the afternoon of their disappearance. the farmer who had identified Tessno as the man fleeing from his mutilated sheep and the circumstantial evidence linking Tessno to the 1898 Lechan murders where the same excuse would die had allowed him to escape justice. The defense called six psychiatrists who testified that Tessna was insane at the time of the murders.

[00:16:59]Several additional psychiatric experts testified for the prosecution, stating that Tesnau had acted in a state of degenerate moral responsibility, a term of the era that acknowledged diminished moral capacity without granting legal insanity. The jury deliberated. The verdict was guilty on both counts of murder. Tessno was sentenced to death by beheading with an additional sentence of 2 years imprisonment for the charge of murderous assault. He was also sentenced to the forfeite of all his political rights. Tessnau appealed his conviction.

[00:17:34]On the 14th of March 1904, the appeal hearing at the Reichskar in Leipig, the highest court of the German Empire, confirmed the judgment. According to the prevailing historical accounts, Ludvik Tesnau was executed by Guillotine in the courtyard of Graveswald prison in 1904.

[00:17:54]He was approximately 32 years old.

[00:17:56]However, the circumstances of his death are not entirely settled. A defense lawyer later claimed that Tessnau's death sentence was secretly commuted to life imprisonment in a house of correction. No contemporary records have been found to confirm the execution definitively, and some sources claim Tessno died as late as 1939.

[00:18:18]The weight of historical evidence favors the execution account, but intellectual honesty requires noting the ambiguity.

[00:18:26]What is not ambiguous is the outcome of the trial itself. Levik Tessnau was convicted of the murders of two children on the strength of forensic blood analysis. The first time in the history of criminal justice that evidence had been used to secure a conviction. The significance of the Tesno case extends far beyond one carpenter in one courtroom. It marks the moment when forensic science crossed a threshold.

[00:18:52]From the identification of substances to the identification of their origins.

[00:18:57]Before Ulen Houth, a forensic examiner could say, "This is blood." After Ulen Huth, that same examiner could say, "This is human blood." And in a criminal investigation, the difference between those two statements was the difference between a quiddle and conviction. To understand the precipitant test in plain terms, the principle rests on the specificity of the immune response. When a foreign protein, say human blood, is injected into a rabbit, the rabbit's body produces antibodies that are uniquely shaped to bind with that specific protein. When serum containing those antibodies is later mixed with a dissolved sample of human blood, the antibodies lock onto the human proteins and pull them out of solution, forming a visible cloudy precipitate. If the sample is animal blood or wood dye or any other substance, no reaction occurs.

[00:19:49]The test is binary and unmistakable.

[00:19:52]Either the precipitate forms or it does not. On the 8th of September 1903, just over two years after Ulin Huth submitted his report on Tesnau's clothing, the precipitant test was officially introduced as courtp proven evidence throughout Prussia. The technique was subsequently extended to the identification of other bodily secretions, including saliva and semen, opening entirely new avenues of forensic investigation. Bulan Huth went on to a distinguished academic career holding chairs at the universities of Strawber, Marborg and Fryborg. He was nominated for the Nobel Prize in medicine 40 times between 1910 and 1952, notably by Nobel laurate Carl Lsteiner, the man who discovered the [ __ ] blood group system he never won. But his contribution to forensic science is difficult to overstate. The precipitant test remained the standard method for species identification in blood stain analysis for most of the 20th century until it was eventually superseded by DNA profiling in the 1980s and '90s. It is no exaggeration to say that the modern forensic laboratory, the world of DNA databases, cerological testing and biological evidence, traces its conceptual origins to a workbench in Graveswald in the summer of 1901 and to a biologist who looked at a carpenter stained clothing and refused to take his word for it. The Tesno case is a landmark of forensic progress, but it is also a story of systemic failure. In 1898, Ludvik Tessnau murdered two 7-year-old girls, was identified by an eyewitness, was arrested with stained clothing, and was released because the science did not yet exist to contradict his lie. 3 years elapsed. In those 3 years, Tessnau relocated to Rugen. He mutilated a farmer's sheep and then he murdered two more children. The question that haunts this case is not whether the science worked. It did brilliantly. The question is whether the systemic failures of 1898 could have been mitigated even without the precipitant test. Testno was a suspect with no alibi, an eyewitness placing him at the scene, a missing button matching one found beside the victims and clothing covered in stains he could not satisfactorily explain. He was calm, composed, and cooperative. A demeanor that in the prevailing psychology of the era was taken as evidence of innocence because the assumption was that only a visibly disturbed person could commit such acts. This assumption cost two more children their lives. The lesson is not that science alone can deliver justice.

[00:22:35]The lesson is that justice requires both rigorous science and the institutional willingness to act upon the evidence available. Even when that evidence is circumstantial, even when the suspect does not conform to expectations, even when certainty is incomplete, the precipitant test did not make the police smarter. It made them more certain. And in a legal system that demands proof beyond reasonable doubt, certainty is everything. Four children died in the cases attributed to Ludvig Tessno.

[00:23:06]Hannah Hydeman, 7 years old, found in the woods near Lectingan on the 9th of September 1898. Else Langmire, 7 years old, found nearby the same evening.

[00:23:17]Herman Stub, 8 years old, found in the woodland near Guran on the 2nd of July 1901. Peter Stub, 6 years old, found beside his brother. They were not footnotes in the history of forensic science. They were not case studies, not data points, not abstractions. They were children who walked out of their homes on ordinary mornings and were subjected to [music] violence that no clinical language can adequately convey. The science that convicted their killer is rightly celebrated. Paul Oolen Houth's precipitant test changed the course of criminal justice. It proved that stains could speak, that the truth could be extracted from fabric, from dried residue, from the molecular traces left behind by the act of violence itself.

[00:24:04]Every DNA analysis conducted in every crime laboratory in the world today is a descendant of that work. But the science existed to serve the dead. It existed because Hannalore and else and Herman and Peter deserved an answer. It existed because a lie, its only would die, had been allowed to stand unchallenged for 3 years. And the cost of that silence was measured in the lives of two more children. This episode is dedicated to their memory, not to the science, not to the killer. To them, this has been the Crimson Files. Until next time, stay safe, stay curious, and remember the ones who couldn't speak for themselves.

[00:24:42]If this episode stayed with you, if the intersection of science and justice matters to you, share it, leave a comment, tell us what case you would like investigated [music] next. Every subscription, every share, every notification bell helps this channel grow and it ensures that these stories, the ones that changed the world but were forgotten by it, reach the people who need to hear them. Thank you for listening.