Rue Basse is a single street in Burnhaupt-le-Haut, a village south of Mulhouse in Alsace that had about a thousand inhabitants in 1994. Between January and April of that year, three elderly women who lived on it were found dead in their beds, each lying on her back with the covers drawn up neatly. Doctors recorded the deaths as natural. One family asked the prosecutor's office to look further, autopsies were ordered, and the report again concluded that nothing was suspicious. In each house, money was missing.
Twelve years later, in September 2006, a 46-year-old Mulhouse gardener named Yvan Keller, arrested in an investigation into burglaries, told police that he had killed those three women, and others. He repeated his admissions before an investigating judge on Friday, September 22, 2006, and was placed under formal investigation for murder over five deaths. A few hours later he was found hanged in a holding cell in the basement of the Mulhouse courthouse.
Because he died before any trial, no court ever ruled on whether he killed anyone after 1989. What exists is his confession, partly retracted; the work of the investigators who tried to check it; and the accounts of families who had long doubted that their mothers died in their sleep.
The French press described Keller as coming from a family of settled Travellers in Mulhouse, basket makers by trade (vanniers). The Italian daily Corriere della Sera, in a 2017 retrospective, wrote that he was one of ten children. He had a criminal record well before 1989. In 1982 he committed an armed robbery at the home of an antique dealer and his wife in Battenheim, a village north of Mulhouse. In 1984 the Haut-Rhin cour d'assises, the French court that tries serious crimes, sentenced him to ten years in prison. Le Parisien reported that he had already spent two years in pretrial detention and that he served about seven years in all. The Dernières Nouvelles d'Alsace (DNA) added that he had other convictions for fraud and burglary in Strasbourg and Mulhouse.
He left prison in August 1989. Investigators would later treat that month as the start of the period they examined.
After his release Keller worked as a gardener (paysagiste), going from village to village and approaching clients directly, according to Le Parisien. Corriere della Sera, drawing on the French coverage, described a well-regarded worker who presented himself well: thin, brown-haired, with large blue eyes. He lived with his partner in a tidy apartment, looked after his neighbors' pets when they went on vacation, and attended the Sacré-Cœur parish in Mulhouse. Neighbors described him as quiet and reserved.
Investigators found a second, much more expensive life. Le Parisien reported that he gambled at the casino in Niederbronn-les-Bains and bet on horse races, and that he and his partner spent weekends at the best restaurants in Paris and London. Corriere della Sera wrote that he stayed at the Ritz, the Bristol and the Pavillon de la Reine in Paris, collected dinners at starred restaurants and took vacations costing tens of thousands of euros. Police were later quoted as saying he had lived "like a lord" on what he stole.
A childhood friend, François de N., a former nightclub doorman who had served a year in prison for robbing a tobacco shop, told Le Parisien in October 2006 that he had driven Keller to three burglaries in the early 1990s, one in Bantzenheim and two in Wittenheim. He said he waited in the car for two or three hours at night, dropped Keller more than a kilometer from where he was going, and was paid 500 or 1,000 francs for his trouble. "But I didn't know he was killing," he said. "Absolutely not." He said he began to have questions in 1992, because Keller had so much cash and spent it gambling, and that he then refused to drive for him again.
Keller's first partner, Marina P., told an investigating judge in 2008 that he had forced her into prostitution in Mulhouse. She had been 18 at the time and, according to Le Parisien, described him as "a madman" and said she was afraid of the Keller family.
Le Parisien counted six occasions between 1989 and 2003 when Keller came to the attention of the police or the courts without result.
The first it described was in December 1991, in Sausheim, just outside Mulhouse. Two sisters in their eighties, Alice and Hélène, had hired Keller to look after their garden. A few hours after his visit they found that a large sum of money was missing from their home. Hélène suspected the gardener at once and reported it to the gendarmes at Illzach. Keller was summoned and questioned, and the Mulhouse prosecutor's office took no further action. According to Le Parisien, one of the two sisters later died, smothered in her sleep. The paper did not give her full name or the date, and no charge was ever brought over her death.
In 1993 de N. went to a friend in the anti-crime brigade (BAC) of the Mulhouse police. He told Le Parisien in 2006 that he had done it because he had an elderly mother himself, "and I thought of all those grandmothers he was smothering in their beds." The officer passed the information to the gendarmerie. When the three deaths on rue Basse came to his attention in 1994, Le Parisien reported, the same officer went to the local gendarmerie brigade with his suspicions about Keller. His statement was written up and nothing came of it. In 1995 another statement pointing the same way reached the prosecutor's office and also went nowhere. Le Parisien reported that the sister of one of the victims had raised Keller's name in 1991 and again in 1995.
DNA reported a further thread: two deaths in 1991 on rue des Blés in Wittenheim, which were revealed to police in the mid-1990s by someone close to Keller. By 2006 those deaths were beyond the statute of limitations for prosecution.
Marie Winterholer was the first. Corriere della Sera, reconstructing the case in 2017, wrote that she was an elderly woman who died in her sleep in January 1994, apparently of respiratory failure, and that relatives and acquaintances at the funeral said quietly that she had gone in the best way possible. Little else about her was published.
Ernestine Mang, 86, lived higher up the same street, at number 11. Her son, Germain, a former employee of the Peugeot plants and a member of the village council, found her dead in bed on Saturday, March 12, 1994. "Maman was lying on her back. The bed was perfect. The blankets were impeccable," he told Le Parisien in 2006. "I called the doctor right away and he told me it was a natural death." Other things troubled him. On entering the house he had stumbled over an old butter churn that was always kept in the cellar, and his mother, whose hips made it hard for her to move, never went down there. Money he had withdrawn for her from the bank, using his power of attorney over her account, was gone. "She wanted to pay for her burial vault with it," he said. Part had been hidden in a drawer of a chest and part in a bag in a wardrobe. Walking around the house, he found that a cellar vent, covered by a wooden screen his father had fitted, had been carefully worked loose. "That's how he got in," he said. He filed a complaint for theft and said he never heard anything more. He also said the gendarmes had suspected him and watched his spending in the weeks that followed. In 2006 he said he wanted only that his word and his doubts be recognized. Corriere della Sera added that Ernestine's granddaughter had noticed that the wooden box where her grandmother kept her savings was empty.
Augusta Wassmer, 77, lived at number 22. Her daughter, Marie-Françoise Roecklin, then living in the neighboring village of Niffer, could not reach her by phone one day in late April 1994 and assumed she had gone to buy geraniums; she was, her daughter said, very independent. A friend raised the alarm when Augusta did not appear for a shopping trip they had planned. Le Parisien gave the date she was found as April 28, 1994; later reports in Le Parisien and Corriere della Sera date her death to April 27.
Her daughter quickly found that Augusta's bank card was gone. It had been used three times in Mulhouse to withdraw cash. A key to the house was never found. There was no sign of a break-in. "The position of the body in the bed was strange. The sheets were pulled too tight. Everything was too neat," Marie-Françoise Roecklin told Le Parisien. Corriere della Sera added that her mother always slept on her side and, because she complained of the heat, would never have pulled the sheets up so high. An autopsy, which Corriere dated to May 11, concluded that she had died of cardiac arrest, probably "due to a great fear," in the words Le Parisien quoted.
The gendarmes did investigate, but in a way the family called careless. Marie-Françoise, her husband, Pierre, and their two sons were questioned separately at different gendarmerie brigades so that their accounts could be compared. "We were taken for fools by the gendarmes. They didn't take us seriously when we were surprised by certain details," she said in 2006, adding that she had felt wrongly suspected. One of her sons, Nicolas Roecklin, Augusta's grandson, was among those suspected at the time, Le Parisien later reported. He would become one of the most persistent voices among the families.
Only two other deaths have been tied to a named woman in the press. Corriere della Sera named Madeleine Schaal, who died on the night of February 12, 1995, at her home in Eschau, south of Strasbourg, and quoted her daughter-in-law, Roseline Lesecq, speaking to Le Figaro: one day the police knocked on the door to say that her mother-in-law was one of the confirmed victims. "It was devastating, the ground fell out from under our feet," she said. Every court summons made the family relive it. "We would have preferred to know nothing, to live with the idea that our Madeleine had died a beautiful death."
DNA reported that one of the five deaths placed under investigation in 2006 was in Gerstheim, in the Bas-Rhin, and that another was elsewhere in the Bas-Rhin in the early 2000s. The names of those two women were not reported.
In 2000, Le Parisien reported, the gendarmerie's research section in Strasbourg was investigating a series of six burglaries in the Bas-Rhin, and a judicial investigation against persons unknown was opened at the court in Saverne under investigating judge Jean-Baptiste Poli. The tip was specific. It came from Pierre K., Yvan's older brother, who gave the addresses of houses that had been robbed. Le Parisien attributed the denunciation to disputes over dividing the proceeds and to family score-settling. Pierre K. named his brother, his brother's partner and a third woman. The three were questioned. The evidence was lacking, the investigation was closed on March 30, 2001, and the judge dismissed the case on April 25, 2001.
On June 24, 2003, Pierre K. denounced his brother again, this time to Daniel H., an officer of the anti-crime brigade in Mulhouse, according to Le Parisien. The officer put him in touch with the Mulhouse criminal brigade and the judicial police (PJ). DNA reported that a preliminary inquiry was opened in 2003 and that Keller was kept under close surveillance for months by the judicial police and the Mulhouse sûreté. The officers worked under a rogatory commission, a judge's delegation of investigative powers, in a judicial investigation into burglaries committed up to 2003 across the south of the Haut-Rhin, which also covered the two 1991 deaths on rue des Blés in Wittenheim.
De N. told Le Parisien he had also come forward again around 2003, and that he was the one placed under investigation. He believed he had been promised protection for helping the police. "They didn't keep their word," he said.
Police arrested Keller in September 2006, together with about fifteen other people from the Mulhouse basket-making community, DNA reported. DNA gave the date as September 20; Le Parisien wrote that he was arrested on the Thursday, which was September 21. The arrests were made in the burglary case.
In custody, he began to talk. According to the accounts that Mulhouse prosecutor Régis Delorme gave the press, Keller said he picked out elderly people, mainly women living alone, entered their homes at night, smothered them in their beds with a pillow and then stole their money and jewelry. Agence France-Presse, in a dispatch carried by La Dépêche du Midi, reported that he said he entered without breaking in, and that he described operating across the border region of France, Switzerland and Germany within about 60 kilometers of Mulhouse since his release in August 1989. Le Parisien, citing investigators in 2007, described a different pattern of entry: forcing a gate or breaking a cellar vent.
The accounts differ on how many deaths he admitted. AFP reported that he said he had killed about thirty elderly women over seventeen years. Le Parisien's first report said he admitted eight killings in the judge's office; its later reports said at least seven. DNA and L'Alsace reported that at one interview he spoke of 150 victims. DNA wrote that he said it "out of defiance or boasting," and L'Alsace reported that he refused to sign that statement.
Corriere della Sera's 2017 account of the interviews goes further than the other reports. It said that Keller gave precise coordinates for at least seven killings and then proposed a bargain: he would tell everything and take investigators to every scene if they kept his partner out of it and gave her protection and a new identity in another city. When the investigating judge replied that he could give no guarantees at that stage, Keller said he refused to sign the record of the interview and that what he had said had no value. Asked how many people he had killed in all, he answered, "One hundred and fifty." The same article quoted his explanation of his method: most of the time nothing happened, "but if the owner woke up, then I took a pillow and put them back to sleep."
Keller also named accomplices. He accused de N. of being with him at the three rue Basse deaths. De N. was placed under investigation for complicity in murder and released under judicial supervision the same day. He told Le Parisien that he had been in prison at the time of the first two Burnhaupt deaths and that police were checking the third. "My best alibi is prison," he said, adding that Keller had wanted revenge when he saw him after the arrest. Le Parisien reported in October 2006 that the checks confirmed he had been in prison then.
Delorme told reporters that five of the confessed killings had been described precisely enough to be identified: three on rue Basse in Burnhaupt-le-Haut between January and April 1994, and two in the Bas-Rhin in 2000 or 2001. For those five, AFP reported, the judge considered that there was enough evidence to place Keller under formal investigation. Keller declined to give places and dates for the others. Delorme said Keller had "provided details that allow one to believe in his sincerity" and that "it would be premature to characterize these statements as coming from a fantasist."
After repeating his admissions before investigating judge Matthieu Bonduelle on Friday, September 22, Keller was taken back down to the holding cells beneath the Mulhouse courthouse at about 1:30 p.m., Le Parisien reported. He was waiting to appear before the judge who decides on pretrial detention, and so, the prosecutor explained, he was no longer formally in police custody. His shoelaces had been left with him. He braided them into a cord and hanged himself from the cell's light fixture. DNA gave the time as 2 p.m.; Corriere della Sera wrote that he had asked for a pizza for lunch and was found at 2:10 p.m. Le Figaro, in an article now behind its paywall, said he hanged himself on the Saturday; the other sources opened say Friday.
The prosecutor opened a judicial inquiry against persons unknown for involuntary homicide through negligence, aimed, Le Parisien reported, at the two police officers responsible for guarding the court cells. "One can have doubts about the actual supervision," Delorme said. What came of that inquiry has not been reported.
Keller's death ended any prosecution of him. Under French law, as DNA put it in 2012, the public action died with him, and in law he remains presumed innocent. The investigation continued against possible accomplices and to establish what had happened.
On October 4, 2006, Delorme told a press conference, as reported by AFP in Le Nouvel Observateur, that the case was "a criminal case without precedent. One could have said it was the criminal of the century." He also said the file would "remain embryonic," because Keller's death meant it would probably be impossible to prove everything. Apart from the three 1994 deaths and two others "in 2000 and 2001 in the Bas-Rhin," he said, "several dozen acts were confessed." Investigators would work with counterparts in Germany, Switzerland and the Benelux countries. A week earlier, AFP had reported that police in Baden-Württemberg and the Swiss cantons concerned had not yet received any request from the French authorities.
The national police office for violent crimes against persons (OCRVP) was sent to Alsace, Le Parisien reported in April 2007. Working with the Mulhouse judicial police, officers went through civil registers and death notices in the local press and asked mayors and older residents what they remembered. Every woman in her seventies or eighties who had died at home was put on a list to examine, and the deaths were sorted against the pattern Keller had described: retired women living alone in modest houses, a death by suffocation in a house with no one else in it, valuables taken. In one Haut-Rhin village, the paper noted, the woman they were looking for shared her surname with half the population. Le Parisien also reported that Keller's DNA had been found in the Swiss home of an elderly woman who died in the early 1990s. No further detail of that case was found in the sources opened.
By April 2007, after more than six months, the judicial police attributed 23 deaths between 1989 and 2006 to Keller, according to Le Parisien, which stressed that the count was not final. "He is without any doubt one of the most active killers of recent years," an investigator told the paper. "Above all he had the cunning to have a method that allowed him to last." L'Alsace later wrote that the police investigation attributed at least 25 killings to him. In 2012, DNA reported talk of well over thirty, perhaps forty, and Le Républicain Lorrain cited a source close to the investigation putting the number of suspected killings at close to forty. In 2013 the families' lawyer, Didier Seban, wrote that the investigation had identified 29 victims, plus two abroad, and that the list might not be complete.
In early summer 2008 investigating judge Marie-Blanche Régnier placed two more people under formal investigation for complicity in murder: Pierre K., the older brother who had denounced Yvan, a scrap metal dealer, and Marina P., the former partner. Both were left free. Le Parisien called it a turnaround, since the Mulhouse prosecutor's office had until then been arguing for a general dismissal because the main suspect was dead. Marina P. told the judge: "I admit that I went with him once. It was in Altkirch or Dannemarie. I don't remember. I did not take part in the murder. I was in the next room." Pierre K. told the judge he did not care about being placed under investigation.
Nicolas Roecklin was now represented by Seban, who said the case should establish the criminal responsibility of accomplices "because Yvan Keller could not have acted alone for so long," and that the families had a right to the truth, "especially since a fault was committed in leaving the suspect able to kill himself."
The case then stalled. In February 2012 the investigating judge, Jacques Bourguignon, met about fifteen families who were civil parties and indicated that he was likely to dismiss the case, DNA reported. The families also learned that evidence had gone missing. L'Alsace, citing Le Parisien, reported that samples taken from the duvet of Augusta Wassmer had been lost before they could be analyzed in Marseille for traces of a possible accomplice. Corinne Herrmann, a lawyer for the families, called it a "judicial disaster."
The Mulhouse court answered publicly. "We have lost nothing," the court's president, Jean-François Beynel, told reporters, as reported by Le Républicain Lorrain on February 25, 2012. He acknowledged that the duvet had been mislaid for a time, but by a laboratory commissioned to take samples in 2010, which had lost it and hair samples while moving from Strasbourg to Marseille. Prosecutor Hervé Robin said the duvet had since been found in Marseille. He also explained why it was the only item left: in 2005 the court had destroyed all the other evidence from the 1994 death once the limitation period had passed, since the death was still classed as natural and that classification was not questioned until 2006. "Only the duvet had been kept, by mistake," he said.
On May 24, 2013, the two investigating judges then in charge, Stéphane Galland and Valérie Messer-Tin, dismissed the case against Pierre K., Marina P. and François de N. for lack of sufficient evidence, and informed the civil parties by letter. "It's a judicial farce. A debacle. The justice system has mocked us from the start," Nicolas Roecklin told Le Parisien. Seban, acting for nine civil parties, announced an appeal to the investigating chamber of the Colmar Court of Appeal. He argued that some acts involving accomplices had wrongly been treated as time-barred, that the courts should have applied the case law used in the Émile Louis and Michel Fourniret serial-killing cases, and that some forensic samples had disappeared without explanation. These were the claims of the families' counsel. The outcome of the appeal was not found in the sources opened; Corriere della Sera wrote in 2017 that all three had been cleared for lack of evidence.
On February 27, 2009, the Mulhouse court ordered the French state to pay 10,000 euros to Keller's last partner, Séverine B., because of its failure to protect him while he was in its custody. The state did not appeal. L'Express reported in May 2009 that she had been compensated while the families of the victims had received nothing. Nicolas Roecklin said in 2013 that she had never been placed under investigation even though she had benefited from the proceeds of the thefts. "They traveled, they dined in the finest restaurants, and all we have left is our eyes to cry with," he said.
By the time Corriere della Sera revisited the case in August 2017, no one had been tried for any of the deaths attributed to Keller, and the three people investigated as accomplices had been cleared. Le Parisien had described the case as definitively closed in May 2013, although the families' lawyer said that month that he would appeal. In October 2021, France 2 devoted an episode of its series Au bout de l'enquête, presented by Marie Drucker with the criminologist Alain B., to the case, under the title "L'affaire Yvan Keller, le plus grand tueur en série français ?" ("The Yvan Keller case, the biggest French serial killer?").
Confessed: Keller admitted to the police and to an investigating judge in September 2006 that he had smothered elderly people during burglaries. He described five deaths precisely enough for them to be identified, and was placed under formal investigation for them. He also retracted, refused to sign at least one statement and tried to trade his account for protection for his partner.
Attributed: after his death, the judicial police attributed 23 deaths to him by April 2007. Later figures, at least 25, about 40, and 29 plus two abroad, come from press reports and the families' lawyer, not from any court finding.
Claimed: the figure of 150 comes from Keller himself. DNA called it defiance or boasting, and Corriere della Sera called it probably a provocation.
Unresolved: whether anyone helped him. Keller named accomplices, de N. said he only drove him to burglaries, Marina P. said she was in the next room once, and the judges found insufficient evidence against all three. His statements about Switzerland and Germany were not tested in any court, beyond the report of his DNA in a Swiss home.
Never tested: none of this was examined at a trial, and in French law Keller died presumed innocent.
1982: Armed robbery at the home of an antique dealer couple in Battenheim.
1984: Sentenced by the Haut-Rhin cour d'assises to ten years in prison.
August 1989: Released from prison.
December 1991: Two elderly sisters in Sausheim report a theft after Keller's visit as their gardener; no action is taken.
1991: Two deaths on rue des Blés, Wittenheim, later reported to police and later time-barred.
1993: François de N. reports Keller to a Mulhouse police officer.
January 1994: Marie Winterholer dies on rue Basse, Burnhaupt-le-Haut.
March 12, 1994: Ernestine Mang, 86, found dead at 11 rue Basse.
April 27 or 28, 1994: Augusta Wassmer, 77, found dead at 22 rue Basse.
1994 and 1995: Further statements naming Keller reach the gendarmerie and the prosecutor's office without result.
February 12, 1995: Madeleine Schaal dies at home in Eschau (later counted among the victims).
2000: Saverne inquiry into six Bas-Rhin burglaries opens on a tip from Pierre K..
2000 or 2001: Two deaths in the Bas-Rhin, including one in Gerstheim, later placed under investigation.
April 25, 2001: Saverne inquiry dismissed.
June 24, 2003: Pierre K. denounces his brother to a Mulhouse police officer; preliminary inquiry and surveillance follow.
2005: Mulhouse court destroys most evidence from the 1994 deaths after the limitation period.
September 20 or 21, 2006: Keller arrested with about fifteen others in a burglary investigation.
September 22, 2006: Repeats his confession before judge Matthieu Bonduelle and is placed under formal investigation for five deaths; found hanged in a court cell that afternoon.
October 4, 2006: Prosecutor Régis Delorme speaks of a case "without precedent."
April 2007: Judicial police attribute 23 deaths to Keller.
Early summer 2008: Pierre K. and Marina P. placed under investigation for complicity in murder.
February 27, 2009: The state ordered to pay 10,000 euros to Keller's partner.
February 2012: Families told a dismissal is likely; dispute over a lost duvet.
May 24, 2013: Case against the three alleged accomplices dismissed; families' lawyer announces an appeal.
October 2021: France 2 broadcasts a documentary on the case.