La police scientifique n’a jamais été aussi performante qu’aujourd’hui. Grâce aux avancées technologiques, les enquêtes criminelles bénéficient désormais d’outils d’investigation pointus, permettant notamment de résoudre des affaires de meurtre, de viol, de vol à main armée ou encore de terrorisme. Dans ce contexte, le concours de la Police Scientifique revêt une importance capitale, car il permet de recruter de futurs Techniciens de Police Technique et Scientifique (TPTS), chargés d’intervenir rapidement sur les scènes de crime.
Un soutien essentiel pour la Police Judiciaire
En effet, l’expertise de la police scientifique fait gagner un temps précieux à la Police Judiciaire, que ce soit dans la gestion d’une scène de crime (homicide, assassinat, etc.) ou d’une scène de délit (vol, cambriolage, dégradations, trafic de stupéfiants). L’analyse d’indices tels que les empreintes digitales, l’ADN, les fibres, les éléments balistiques ou encore les traces numériques contribue à établir des preuves solides face aux tribunaux et permet de mieux cerner le profil des suspects.
L’importance du facteur humain
Malgré ces moyens technologiques de pointe, les effectifs de la police scientifique restent profondément humains. Chaque jour, ces professionnels doivent composer avec des situations parfois dramatiques et faire face à la détresse des victimes. Dans l’émission LEGEND sur YouTube, animée par Guillaume Pley, le policier scientifique Sébastien Aguilar, souligne l’impact psychologique de ces enquêtes. Il évoque des affaires hors du commun, parfois totalement folles, mais aussi des cas dont la violence l’a marqué pour toujours.
Police Scientifique : un métier loin des clichés
Cette réalité du terrain est souvent bien différente des clichés véhiculés au sujet de la police scientifique. Dans son ouvrage « Au cœur de l’enquête criminelle », publié dans la collection Darkside chez Hachette, Sébastien Aguilar décrit pas à pas le travail rigoureux des enquêteurs, épaulés par les policiers scientifiques entièrement dédiés à la recherche de la vérité. Il y relate également les différentes étapes qui mènent au procès en Cour d’Assises, offrant un aperçu complet du fonctionnement de la machine judiciaire.
Si vous souhaitez en savoir plus sur l’impact psychologique du métier, les techniques d’investigation modernes ou encore l’importance du concours de Technicien de Police Technique et Scientifique, retrouvez l’interview de Sébastien Aguilar par Guillaume Pley sur YouTube et plongez-vous dans « Au cœur de l’enquête criminelle » pour une immersion totale dans l’univers passionnant de la police scientifique.
As Public Prosecutor in Charleville-Mézières from 2003 to 2008, I was in charge of the Fourniret/Monique Olivier case for four years and, at their assize court trial, secured their conviction to life imprisonment. It was an exceptional case—by the number of young girls and adolescents who fell victim, by the length of the criminal trajectory of this serial killer couple, by the abomination and inhumanity of the crimes committed, and by the unprecedented perversity of these two monsters.
It took me 15 years after the 2008 trial to write my book Ma rencontre avec le Mal (My Encounter with Evil), which is not a journalistic narrative of these heinous crimes but rather the writing of my lived experience—my share of truth. It is an attempt to contribute to the understanding of the particular handling that major criminal cases and serial crimes require, as well as the legal, criminological, and social challenges they present. Above all, my book was intended to help others understand, at least in part, the terrible and irreversible torment endured by the families of these unfortunate victims, so that they might be better heard by the justice system, granted genuine attention, and shown constant empathy throughout their arduous judicial ordeal.
The chilling discovery of a serial killer
Upon my appointment as Public Prosecutor in Charleville-Mézières in 2003, I was immediately made aware of two very serious criminal cases: the abduction and murder of two young victims. On May 16, 2000, Céline, aged 18, disappeared after leaving her high school in Charleville-Mézières. Any suggestion of a runaway was quickly dismissed, and although searches began immediately, they remained fruitless until July 22, 2000, when her skeletal remains were discovered in nearby woodland close to the Belgian border. On May 5, 2001, Mananya, aged 13 and a half, disappeared in Sedan, an Ardennes town, as she left the public library and was returning home. On March 1, 2002, her body was discovered about 30 kilometers away, near a Belgian village. The analogies between these two crimes were far too numerous to suggest coincidence: the geographical proximity of the events and of the sites where the bodies were found, the modus operandi of urban abductions carried out discreetly, the details of how the bodies were abandoned, the victims’ physical and psychological profiles… Together with the investigating judges and investigators of the Reims police judiciaire, the frightening hypothesis of a serial killer operating in the Ardennes became increasingly credible. Despite multiple investigations conducted jointly by the judicial police of Reims and Dinant in Belgium, the searches remained unfruitful. That was until June 26, 2003, when a major event reignited both inquiries. On that day, a 13-year-old girl, Marie-Ascension, was abducted in Belgium. Thanks to her courage and composure, she managed to free herself from her restraints and escape from the van in which her abductor had confined her. A motorist picked her up and, with remarkable presence of mind, took note of the vehicle’s license plate. The gendarmes traced it to Monique Olivier, wife of Michel Fourniret. Fourniret was quickly arrested. He admitted to the facts and stated that he had tied up the girl, touched her breasts, considered having sexual relations with her, and told her that “he was far worse than Dutroux.”
Searches carried out at his home revealed children’s clothing, ropes, adhesive tape, a pair of handcuffs, a child’s inhalation mask, vials of ether, and various weapons, including police revolvers stolen during a burglary.
Fourniret agreed to kill Monique Olivier’s two previous partners, and in exchange, she would provide him with young virgin girls, whom they referred to as “MSPs (membranes on legs)” or “young slits.”
Michel Fourniret and Monique Olivier: the deadly alliance of a serial killer couple
Monique Olivier claimed to be completely unaware of her husband’s proclivity for children, denied any awareness of his prior convictions, and asserted—like Fourniret—that this abduction was an isolated case. It would take a full year, the relentless work of Belgian investigators who questioned her 120 times, and the covert recording of a prison visitation, before she finally gave her first confession—very partial—regarding the number of crimes committed and her own role. A few days later, confronted with the details provided by his wife, Fourniret confessed as well. He explained that he had met Monique Olivier while serving a sentence for previous sexual assaults. She had responded to his request for a pen pal, and over the course of eight months they exchanged more than 200 letters. The analysis of this voluminous correspondence is chilling: even before meeting in person, they had sealed a genuine criminal pact. Fourniret promised to kill Olivier’s two former partners, and in return, she would provide him with young virgins girls, whom they referred to as “MSPs (membranes on legs)” or “young slits.” Two months after Fourniret’s release, this pact—until then confined to paper—was put into practice, with devastating consequences for Isabelle, aged 17.
On December 11, 1987, Isabelle disappeared on her way home from school in Auxerre. The couple’s later confessions revealed the meticulous planning of this abduction: surveillance beforehand, the kidnapping of the girl by Monique Olivier, Fourniret pretending to have run out of fuel before climbing into the vehicle, slipping a cord around her neck, while Olivier administered Rohypnol tablets that rendered her semi-conscious. Brought to their home, Fourniret attempted to rape her but was unable to do so due to erectile failure. Acting on her own initiative, Olivier performed oral sex on him. Fourniret then strangled the girl, and together they disposed of her body by throwing it into a disused well. It would take more than two years and the exploration of some thirty old wells before her remains were finally recovered—a heart-wrenching moment for Isabelle’s father. The murders continued one after another, as the bloody trajectory of the couple stretched on for 16 years.
In January 1988, Fourniret, accompanied by Monique Olivier, shot a sales representative at point-blank range with a shotgun in order to rob his wallet. This act of violence was consistent with one of their written agreements. The victim miraculously survived.A few weeks later, they committed another murder by killing the partner of one of Fourniret’s former fellow inmates, in order to steal part of the loot from the Gang des Postiches, a notorious group of bank robbers active in the Paris region. This allowed them to purchase, for 1.2 million francs, the Château du Sautou, a 19th-century castle with a park of about fifteen hectares. A criminal episode as bizarre as it was deadly. In August of the same year, they abducted and murdered Fabienne, a 20-year-old student, in the Marne. Fourniret first tried to kill her by injecting air into her veins with a syringe, then shot her at point-blank range with a sawed-off shotgun. They abandoned the young woman’s body on the Mourmelon military base, echoing the crimes committed by another serial killer, Adjutant Chanal.
In January 1989, the couple abducted Jeanne-Marie, a 21-year-old student, in Charleville-Mézières. After attempting to rape her, Fourniret strangled her while Monique Olivier sealed her nasal and oral passages with adhesive tape. They buried her body on their property at the Château du Sautou. Her remains would not be found until 15 years later, after searches complicated by Fourniret’s manipulations and provocations. In December 1989, near Namur in Belgium, Monique Olivier used the pretext of her sick infant—lying in a cradle at the back of her vehicle—to abduct 12-year-old Elisabeth together with Fourniret. After bringing her to their Ardennes home, intoxicating and tying her up, Fourniret attempted to rape her—again unsuccessfully, despite another act of oral sex performed by Monique Olivier. Elisabeth spent the night in chains, before being taken the next day by Fourniret to the Château du Sautou, where he suffocated her in a transparent plastic bag. During a later “conversation,” he tried to provoke me by odiously recounting in detail the physical transformations of a face undergoing asphyxiation.
Un mode A modus operandi strikingly similar to that of another serial killer, Francis Heaulme. similaire à celui d’un autre tueur en série, Francis Heaulme.
In November 1990, they abducted Natacha, 13, from a supermarket parking lot near Nantes. Fourniret brutally beat her, raped her, and stabbed her repeatedly with an awl. He abandoned her body on a beach in Vendée, 80 kilometers away—a modus operandi strikingly similar to that of another serial killer, Francis Heaulme. In 1995, Fourniret violently assaulted a dog groomer in Namur. Thanks to her presence of mind, the victim, Joëlle, survived, though she still suffers permanent psychological trauma to this day—a genuine psychological murder. In 2000 and 2001, he abducted, raped, and killed Céline and Mananya in the Ardennes, after subjecting them to prolonged psychological torture. An endless ordeal for these two young victims.
Between 1990 and 2000, far from being a “quiet period,” the couple’s criminal activities continued at a relentless pace. Crimes were committed, such as the murder of young Estelle in Guermantes, near Paris—solved 16 years later—as well as numerous attempted or aborted abduction, rapes and murders plans.
Michel Fourniret: the most “accomplished” serial killer
A deep dive into the tortured psyche of a diabolical couple
How can such extreme and murderous deviations be explained? Nothing in the past lives of either Fourniret or Monique Olivier provides the faintest beginning of an answer. Only their numerous psychological and psychiatric evaluations have managed to lift part of the veil.
Fourniret has been described as “the most accomplished serial killer.” Of chilling coldness, highly organized and obsessive, sadistic, extremely violent and perverse, his criminal pathology was regarded as absolute. He derived genuine pleasure from the terror and humiliation of his victims, prolonging their agony. Monique Olivier, on the other hand, possessed an intelligence quotient far above average. Perverse and manipulative, she managed to make herself indispensable to Fourniret in order to fulfill her own most archaic fantasies. She was the one who gave him his license to kill; “without her, there would have been no murder.” Indifferent to the suffering of their young victims, she took a certain pride in being Fourniret’s accomplice and played a particularly active role in the commission of their crimes. The grip they exerted over each other was total and reciprocal, through “the alienation of each in the fantasy of the other.” Experts spoke of “a genuine co-optation of their unconscious drives, a mechanism so intimate that it gave rise to a new, third entity: the acting couple. It was as if a new subject had been created—two psyches meshed together, driving them toward criminal action.”
Life sentences for an unprecedented verdict
This monstrous couple was convicted in May 2008 after eight grueling weeks of trial. To their insufferable demeanor, the families responded with exceptional dignity—despite their immeasurable and permanent grief—commanding the respect and admiration of all.
Fourniret was sentenced to life imprisonment without parole, in other words, a true whole-life sentence with no possibility of adjustment, reduction, temporary leave, or early release—a sentence rarely imposed in France. Monique Olivier was sentenced to life imprisonment with a minimum security period of 28 years. She remains the only woman ever to have received such a sentence in France.
France had never before witnessed such a monstrous serial killer couple, over such an extended period, targeting such a high number of young victims—likely between thirty and thirty-five, many of whom remain unidentified—tortured under horrific conditions. May such atrocities never be repeated.
“No one will come out of the Fourniret case unscathed—not FRANCIS NACHBAR, not even you, Mr. Prosecutor.”
Fourniret uttered this sentence only minutes after his first encounter with Prosecutor Nachbar. It was on July 3, 2004, during the excavations in the park of the Château du Sautou, in the Ardennes, where the bodies of two of his victims were discovered. The monster was not mistaken. Eighteen years later, those words still resonate like a grim refrain. Indeed, Francis Nachbar did not emerge entirely unscathed from this extraordinary judicial case, from the hundreds of hours spent with Michel Fourniret and Monique Olivier, a diabolical couple and the ultimate embodiment of evil. Fifteen years after the 2008 Assize Court trial, Francis Nachbar decided to deliver his own share of the truth about one of the greatest serial killer cases France has ever known. It took him all these years to feel ready—freed from judicial office and from any constraints.
A vital book that sheds new light on this bloodstained couple. In total, Michel Fourniret confessed to 11 murders. He is also suspected in 21 other cases of missing girls and young women. Available to order here.
As in the Élodie Kulik case in 2011 and that of the “Prédateur des bois” in 2022, two casefiles reopened by the Cold Case Unit in Nanterre are now close to being solved thanks to familial DNA searching,
“They say you’re only betrayed by your own,” a proverb that takes on its full meaning here. Two murders committed twelve years apart and seemingly unrelated have now been traced back to one and the same suspect—thanks to a genetic link established between members of the same family.
In 1988, fifteen-year-old Valérie Boyer was found with her throat slit along the railway tracks in Saint-Quentin-Fallavier. In 2000, forty-year-old Laïla Afif was shot dead in the head in La Verpillière. The only common factor between the two crimes was geographical proximity, as both occurred in neighboring towns in the Isère department. Lacking solid leads or similarities in the modus operandi, the investigations soon came to a standstill—until March 2024. More than twenty years later, the Cold Case Unit, created in 2022, reopened the Laïla Afif case and ordered new DNA analyses on samples recovered from the crime scene.
Proof through familial DNA
These forensic analyses, extended through the use of familial DNA searching, led investigators to identify, within the National Automated DNA Database (Fichier National Automatisé des Empreintes Génétiques – FNAEG), an individual previously implicated in another case whose DNA showed a 50% genetic match with the profile obtained in the Afif case. And as the immutable laws of genetics dictate—each person shares half of their genome with their biological parents and children—the investigators logically traced the lead back to the man’s father. Betrayed by his son’s DNA, Mohammed C. has now been indicted not only for the murder of Laïla Afif, but also for that of Valérie Boyer, as the reopened investigation revealed striking connections between the two crimes. The latter case is part of the notorious “Disparus de l’Isère” (the Isère disappearances) series, a string of disappearances that made national headlines in the 1980s and is already under review by the Cold Case Unit.
Further reading: COLD CASES UN MAGISTRAT ENQUÊTE (Cold Cases – A Magistrate Investigates), by Jacques Dallest
Criminal history is marked by sordid murders, brutal killings, mysterious disappearances, and puzzling suicides. Mysterious and puzzling because these cases have never been solved—the perpetrators never identified, the culprits never convicted. In proper French, these cases are referred to as “cold cases.” They number in the dozens and are often unknown to the general public. Only a few major unsolved cases have found their place in the annals of judicial history and continue to fuel debate and speculation: the Bruay-en-Artois case, the Fontanet case, the Grégory case, the Boulin case, and, more recently, the Chevaline shootings. But what exactly is a cold case? What does this English term signify within the context of the French judicial system? Should these cases be reopened? And after so many years, how can justice still be served? In this scholarly and meticulously documented essay, Jacques Dallest—former investigating judge, public prosecutor, and Advocate General—offers a comprehensive analysis of the issue as no book has ever done before.
Created in 1987,the Automated Fingerprint Identification System (FAED, France) stores various types of data collected during judicial investigations. Its use, strictly regulated by law, was recently modified by a decree issued on April 23, 2024.
As of January 2024, the FAED contained the fingerprints and palm prints of more than 6.7 million individuals, as well as nearly 300,000 unidentified latent prints (CNIL data). Each year, over one million new records are added. This vast amount of information makes the database a valuable tool in criminal investigations, as its consultation allows investigators to establish links between cases or to identify missing persons.
More interconnections for greater efficiency.
The FAED is far from being the only existing database. France operates several others, including the TAJ (Traitement des Antécédents Judiciaires – Criminal Records Processing System), the CJN (Casier Judiciaire National – National Criminal Record), the DPN (Dossier Pénal Numérique – Digital Criminal File), and the FPR (Fichier des Personnes Recherchées – Wanted Persons File), each of which contains millions of data entries. Added to these are the police and gendarmerie procedural software systems, LRPPN and LRPGN, which enable the automated processing of personal data.
The decree, which came into force on April 24, 2024, aims to establish interoperability among these different databases, with the clear objective of facilitating cross-references and improving overall efficiency.
Enhanced European cooperation.
The project does not solely focus on the national level; it also aims to link these national databases with European systems, allowing access to their data repositories. This will notably be the case for the Second Generation Schengen Information System (SIS II), which includes a central unit based in Strasbourg, connected to national databases in each Schengen member state. This system centralizes information on individuals or objects reported by administrative and judicial authorities across the participating countries. Another beneficiary will be the Entry/Exit System (EES), which automatically records and monitors data relating to nationals of non-EU countries traveling within the Schengen area.
In both cases, this data sharing aims to facilitate information exchange, strengthen controls, and consequently enhance security within the European area, now free of internal borders.
Des données suffisamment sécurisées ?
The decree also modifies the retention period for data stored in the FAED. It is now set at twenty-five years for crimes and certain offenses, and may extend up to forty years for specific criminal procedures.
Given the vast volume of data processed and the new interconnections among databases, concerns naturally arise regarding the protection of personal information. Following a warning issued by the CNIL (Commission Nationale de l’Informatique et des Libertés – French Data Protection Authority), which had expressed concerns to the Ministry of the Interior, measures have been implemented to safeguard data confidentiality and to ensure the automated updating and deletion of records once their retention period expires. Whether these measures will prove sufficient remains to be seen…
A seasoned investigator deeply committed to solving cold cases, Raphael Nedilko describes them as “an equation with three unknowns: a complex case file, a family in total incomprehension, and an institution that remains largely deaf despite obvious goodwill at the individual level.”[1]
This is a perfect summary of an issue that continues to raise questions today. Victims and the justice system too often maintain relations as difficult as the case itself. The former cannot understand the inability to solve the crime or the disappearance and perceive only unjustifiable shortcomings. Overwhelmed by massive and urgent litigation, the latter recognizes its inability to devote time to old cases—serious, yes, but moribund in its eyes. It will invoke a lack of resources and an initial, fruitless investigation that would be pointless to reopen.
But what of the investigation that gave rise to the scandal? Is it not itself at fault, plunging families into despair and indignation? And does reopening or relaunching a case require a different treatment from an investigation that, by definition, concerns past events?
The initial criminal investigation: rigor is essential
It is often repeated in police academies and at the National School for the Judiciary (ENM): everything depends on the quality of the initial investigation. Truth lies in the rigor of crime scene observations and evidence collection procedures. These tasks are numerous and sometimes delicate, depending on the configuration of the crime scene. Three scenarios arise, from the simplest to the most complex:
• The crime scene is located in an enclosed space—house, apartment, or their outbuildings. The homicide has clearly taken place there and the victim’s body is present. The perimeter is easy to secure, greatly facilitating the investigators’ work. However, a risk remains: third parties (relatives, neighbors, emergency services, etc.) may have entered the premises before the investigators’ arrival, potentially contaminating the crime scene.
• The crime scene is in a public place. The victim has been killed in the street or in a vehicle (settling of scores). The perimeter is more uncertain and less easily secured, inevitably complicating the search for traces and evidence. The presence of bystanders may also interfere with the investigation. In addition, the event may generate public disorder, particularly if it occurs in a neighborhood prone to urban violence.
• The crime scene is uncertain or ill-defined. This is the most delicate situation for investigators. The body is discovered in a natural environment—forest, woods, dirt path, or aquatic setting such as a river, pond, or the sea. Defining the crime scene may be complex, if not impossible (e.g., an immersed body). Moreover, the presence of the body does not necessarily mean the murder took place where it was found. It is likely that the crime occurred elsewhere and that the perpetrators sought to dispose of the victim. This configuration makes the investigation particularly challenging, especially if the death occurred long ago.
The layout of the crime scene thus directly affects the conduct of the investigation. In any case, the investigative service must display the utmost rigor. It is well known that initial observations are decisive: any omission, oversight, or negligence will weigh heavily on the case. Establishing the truth may be compromised, with errors often proving irreversible.
The uncertainty surrounding the cause of death can also arise. It may be natural, accidental, criminal, or suicidal. Determining the cause ab initio is not always simple. An erroneous initial assessment can gravely distort the reasoning of both investigators and prosecutors. Mistaking a homicide for a suicide—or the reverse—can cause irreparable deficiencies or, conversely, unnecessary and time-consuming actions, whereas prompt investigations are crucial for preserving evidence.
“Solving a murder is a priority task that requires perfect coordination between investigators and magistrates.”
Jacques DALLEST
Careful observation of the location where the body is discovered, thorough and rigorous documentation, preservation of traces and evidence, meticulous collection, and methodical conservation—these are the fundamental recommendations that first responders must respect.
Unfortunately, insufficient staffing, inadequate training, poor equipment, culpable negligence, serious mistakes, and dangerous certainties all hinder the investigation. An incomplete neighborhood canvass, overly hasty interviews, unexecuted searches, and missing verifications likewise contribute to failures that seriously undermine the inquiry.
Magistrates must fully exercise their prerogatives in directing the investigation. The prosecutor involved at the outset and the investigating judge subsequently assigned to the case both play a fundamental role. The absence of precise directives for investigators, or a lack of diligence in case supervision, cannot be justified by an excessive workload. Admittedly, the criminal magistrate is above all a generalist, overwhelmed by urgent cases and daily pressures. However, criminal cases—particularly crimes involving loss of life—demand complete commitment and particular attention to the investigations conducted by the assigned service. Solving a murder is a priority task that requires perfect coordination between investigators and magistrates.
This necessary professional rigor must also account for the expectations of the victim’s relatives, devastated by a terrible tragedy and in deep distress. Distraught, they turn to justice, hoping for attention that is too often insufficient, if not absent. Even when acting as civil parties, they unanimously complain of being kept in the dark regarding the progress of the investigation—and worse, of not being received or heard by the investigating judge. Let us recall that Article 90-1 of the Code of Criminal Procedure obliges the judge to inform the civil party every six months on the progress of the investigation. The same text also allows relatives to be heard by the judge every four months upon their express request.
Sadly, these provisions are often forgotten. Civil party lawyers must insist on their strict application and act proactively in this regard. Too few actually use the rights granted to them by law, instead waiting passively for the investigating judge to summon them. This is most regrettable.
Is the judicial treatment fundamentally different when the crime remains unsolved? What means do investigators and the judiciary have at their disposal to pursue such cases—old, yes, but still profoundly painful for the relatives?
The Chevaline massacre case (2012)The Dupont de Ligonnès case (2011 The Caroline Marcel case (2008)The Estelle Mouzin case (2003)The Tiphaine Véron case (2018)Numerous judicial case files concerning unsolved cases have been transferred to the Nanterre Unit.
Cold case investigations: determination and empathy required
Reopening an old criminal investigation is a delicate task, all the more so when the facts remain unsolved. Past missteps weigh heavily on those tasked with solving the mystery. Forgotten witnesses, overlooked searches, neglected seizures, technical inquiries left aside, ill-suited strategies, and lack of commitment all lead to a dead end—an impasse from which it is difficult to escape. How many mishandled cases have resulted in perpetrators going unpunished? And how many murderers or rapists were able to reoffend simply because they were never identified?
The creation of the Specialized Unit for Serial and Unsolved Crimes (PCSNE), established within the Nanterre Judicial Court on 1 March 2022, has reshuffled the deck. Now, with the new criminal provisions introduced by the Law of 22 December 2021 (Title XXV bis, as incorporated into the Code of Criminal Procedure), the judicial handling of cold cases has gained a momentum that many hope will prove decisive.
The Nanterre Unit now has jurisdiction over violent and sexual crimes (murder, rape), as well as abductions and unlawful confinements committed—or likely committed—repeatedly, at different times, by the same individual against different victims, and more generally, over crimes whose perpetrator has not been identified more than eighteen months after their commission (Article 706-106-1).
Serial crimes and unsolved crimes are thus to be referred to Nanterre, regardless of where they were committed within French territory.
This represents a major step forward—long demanded by victims’ families—which helps restore their hope in justice. Composed of motivated, specialized prosecutors and investigating judges, the Nanterre Unit devotes all its energy to the exclusive handling of cold cases, thereby opening up new prospects for resolution. It is well known that, overwhelmed by urgent criminal matters and mass litigation, generalist magistrates can devote only limited time to old cases, however serious they may be. The first years of the Unit’s operation, and several notable successes, have demonstrated the value of a justice system focused on this highly specific area.
“At the same time, Prosecutors General and Public Prosecutors will have to establish a genuine criminal memory enabling them to know and monitor unsolved cases within their jurisdiction.”
Jacques DALLEST
A genuine “cold case culture,” born of the new law, must now permeate the judiciary. It is already clear that the Nanterre Unit will not have the material capacity to centralize all unsolved crimes in France, some of which date back more than forty years. It is therefore imperative that all Public Prosecutors and investigating judges handling criminal cases fully embrace this new and virtuous dynamic.
Taking genuine interest in these cases, developing tailored investigative methodologies, making use of modern investigative tools (such as artificial intelligence), mastering and applying new scientific disciplines (forensic sciences), reaching out to civil parties and listening to them, learning how to question suspects (behavioral analysis can assist here), forging links with foreign partners where necessary, and working with the media when appropriate—these are all avenues of effort that must guide magistrates in charge of cold cases.
Cold Cases – An Investigating Magistrate’s Inquiry – Jacques DALLEST – Mareuil Editions
At the same time, Prosecutors General and Public Prosecutors will have to establish a genuine criminal memory, enabling them to know and monitor unsolved cases within their jurisdiction. This memory is largely absent in prosecutors’ offices. Upon taking office, a prosecutor will not find on his or her computer a list of unsolved criminal cases, whether ongoing or closed.
Five tables should be regularly updated in the 91 prosecutors’ offices with a criminal division (out of 164 jurisdictions): murders against persons unknown, rapes against persons unknown, abductions and unlawful confinements against persons unknown, discoveries of unidentified bodies (including those buried under the designation “X”), and missing persons cases of concern. These tables would be communicated to the Prosecutor General (36 in France), who would periodically organize evaluation and monitoring meetings with the relevant prosecutors. A pooling of such data and exchanges could also be organized at the interregional level (several courts of appeal), so that each office has a panoramic view of crimes and disappearances recorded across this wider territory. Who can seriously believe that a criminal limits his actions to a single jurisdiction?
A criminal memory is indispensable to better identify violent and sexual crime, to address it with greater determination, to respond usefully to the expectations of relatives and their lawyers, and to be able to face media inquiries.
“One does not question a suspected murderer, possibly serial, in the same way as one questions a drug trafficker or a burglar.”
Jacques DALLEST
Seriously investigating a cold case also requires following these recommendations:
• Never destroy the case evidence, even if the case has been closed. A recent provision, effective 30 September 2024, prohibits any destruction within ten years after the expiry of the statute of limitations, i.e. thirty years after the case has been closed. Criminal evidence must be stored in a dedicated space, preserved in good condition, and carefully tracked. Losing a piece of evidence through negligence is unacceptable, as it may eliminate any chance of success.
• Give special attention to the victim’s relatives, the civil parties: receive them regularly, listen to them, carry out the acts they request, explain the progress and prospects of the case, and treat them simply with dignity. As Raphael Nedilko rightly says, it is a matter of honesty, honor, and humanity.
• Know how to conduct (or re-conduct) witness interviews, which can prove decisive. A sound methodology for collecting testimony is essential. The same applies to suspect interviews: one does not question a suspected murderer, possibly serial, in the same way as a drug trafficker or a burglar.
• Re-examine the work already carried out, not to criticize it as a matter of principle, but to identify shortcomings or omissions.
• Draw connections with similar cases or those showing converging elements. The notion of a “criminal signature” must be set aside: many serial criminals in France act without a consistent modus operandi. The fact that victims differ in age or gender, or that the weapon used to kill them is not the same, does not exclude the possibility of a single perpetrator. Beware of the limits of American-style profiling, which can lead to serious errors.
• Remain constantly informed about scientific advances, which are in perpetual evolution. DNA analysis today is far removed from what it was at its discovery, and the exploitation and evidentiary value of genetic traces will advance considerably in the decades to come.
• Do not rely solely on scientific evidence, which may be lacking. Traditional investigation, with its human dimension, remains indispensable. Commissaire Maigret has not ceded his place to the hard sciences researcher.
• Train in new investigative techniques—digital, computer, telephonic, ballistic, etc.
• Beware of certainties, biases, and preconceived ideas, which lead to tunnel vision from which there is no escape. Excessive self-confidence generates errors that are often irreparable.
• Work not only for the establishment of truth but also for posterity. Other investigators may one day take over. One must ensure not to leave them unable to move forward. Humility is a virtue here, more necessary than ever.
• Never give up, for scientific progress may one day allow the case to be solved. Determination is as necessary as teamwork.
The judicial handling of cold cases is long, uncertain, and demanding. Hope keeps families alive. It must also guide the actors in the case. The investigating judge in charge and the investigators must speak to one another, exchange views, and set objectives. The lawyer for the civil parties—their guide through the judicial maze—cannot be sidelined as if he were an unwelcome figure. He has his rightful place in the proceedings, and his active contribution is required. More than anywhere else, collective intelligence is called upon here. qu’ailleurs, l’intelligence collective est convoquée.
“Man, no one has plumbed the depths of your abysses,” wrote Baudelaire. To attempt it—what greater endeavor could there be?
[1]See his article “Cold Cases: Let Us Give Hope a Chance,” in issue no. 52 of Cahiers de la Sécurité et de la Justice (2021), “Les crimes complexes, cold cases, meurtres sériels, disparitions non élucidées.” See also his excellent book L’obstiné (Studiofact Editions, 2023).
Finies les poudres dactyloscopiques ou les réactifs chimiques pour relever les empreintes digitales ? C’est en tout cas ce qu’espèrent des scientifiques en proposant cette alternative qui pourrait révolutionner les méthodes de police scientifique.
Utilisé depuis le XIXème siècle sur les scènes de crime, le relevé d’empreintes papillaires a déjà connu quelques évolutions techniques depuis sa mise en place. A côté des poudres dactyloscopiques classiques, les agents de la police scientifique disposent aujourd’hui de réactifs chimiques, notamment la ninhydrine, l’indanedione, le DFO ou encore le Lumicyano, une technique luminescente mise au point en 2013 par des experts français, qui utilise du cyanoacrylate fluorescent par fumigation.
Ces différentes techniques présentent toutefois quelques inconvénients : Certaines formulations contiennent des composants qui peuvent se révéler toxiques à fortes doses, elles peuvent dégrader l’ADN présent dans les empreintes (sueur, cellules épithéliales) et nécessitent par ailleurs plusieurs minutes pour révéler une trace.
Inspirantes méduses …
Afin d’améliorer les capacités opérationnelles des équipes présentes sur les scènes de crime, des scientifiques basés en Chine et au Royaume Uni ont mis au point une alternative en s’inspirant … Des méduses ! Ces organismes marins que l’on connaît plus pour leurs piqures urticantes que pour leurs aspects positifs, produisent en effet la GFP (Green Fluorescent Protéin) une protéine fluorescente soluble dans l’eau et compatible avec les systèmes biologiques. Elle a donné naissance à deux colorants, le LFP jaune et le LFP rouge, dont la particularité est d’interagir avec les acides gras et les acides aminés présents dans le sébum et la sueur qui imprègnent les empreintes digitales et dont la formulation est compatible avec les analyses ADN ultérieures.
Un spray actif en 10 sec
Le nébulisateur ultrasonique imaginé par les scientifiques offre l’avantage de vaporiser une brume très fine qui se dépose sans altérer les empreintes. Une fois au contact de la surface à traiter, les molécules des colorants se lient aux sécrétions sébacées et eccrines des empreintes. Il suffit ensuite d’exposer la zone à la lumière U.V pour qu’apparaisse une empreinte claire et contrastée en seulement dix secondes, prête à être photographiée.
Ce gain de temps se double d’une capacité à révéler des traces papillaires anciennes déposées plusieurs jours auparavant et d’une véritable efficacité sur des surfaces réputées difficiles comme la céramique, le plastique, le papier aluminium ou plus rugueuses comme la brique. Des performances qui ont encore besoin d’être optimisées avant que cette nouvelle technique ne soit intégrée dans l’arsenal forensique mais qui ouvre de nouvelles perspectives pour la police technique et scientifique.
En décembre 2023, le site de généalogie génétique 23andme a subi le piratage des données ADN de presque 7 millions de clients. Une cyberattaque qui met en lumière la valeur de ces informations ultrasensibles et pas seulement pour les cybercriminels !
Il suffit désormais d’un test salivaire vendu par des sociétés spécialisées dans la généalogie génétique pour connaître ses origines et identifier ses ancêtres. Un axe ludique revendiqué par les biobanques comme 23andme, MyHeritage ou Ancestry pour ne citer qu’elles. Ces sociétés communiquent en revanche assez peu sur le risque que l’on coure à confier des données aussi confidentielles que son propre ADN, ces informations pouvant être rendue publiques ou faire l’objet d’un trafic très lucratif comme le montre ce dernier hackage informatique.
Construire son arbre généalogique génétique
Les progrès sur les analyses ADN permettent de réaliser des comparaisons de plus en plus fines entre les millions de données génétiques présentes dans ces fichiers informatiques, ces derniers étant régulièrement alimentés par des tests effectués chaque année dans le Monde. Grâce à ces comparaisons, les généalogistes génétiques peuvent retrouver des individus apparentés de façon proche ou lointaine et élaborer ainsi un véritable arbre généalogique avec à la clé, des informations sur des ancêtres souvent totalement inconnus. Une découverte amusante et parfois déroutante sur ses origines.
L’ADN de parentèle pour résoudre les crimes
Au-delà de son aspect récréatif, la généalogie génétique est une technique qui suscite de plus en plus l’intérêt de la police scientifique. Dans ce cas, les enquêteurs confrontés à une enquête qui se trouve dans l’impasse, ne scrutent pas le passé mais se focalisent plutôt sur les branches plus contemporaines de l’arbre généalogique afin de comparer les ADN présents dans ces bases publiques avec un ADN retrouvé sur une scène de crime mais inconnu au FNAEG (Fichier National Automatisé des Empreintes Génétiques). L’objectif est de trouver une correspondance et, en partant de l’identification d’un parent plus ou moins proche, de remonter jusqu’à l’auteur de la trace biologique. Au Etats-Unis, cette technique a déjà permis d’élucider 621 affaires criminelles et en France, grâce aux recherches du FBI, d’arrêter en 2022 celui qui avait été baptisé le « prédateur des bois » à cause de son mode opératoire pour perpétrer plusieurs viols entre 1998 et 2008.
La généalogie génétique pourrait devenir un outil d’investigation très utile pour la résolution de certains « cold case ». En revanche, en France, contrairement aux Etats-Unis où cette pratique existe déjà au grand dam de certains spécialistes des questions éthiques, cette recherche ne peut pas s’effectuer en piochant dans les bases de sociétés privées mais uniquement dans les bases génétiques créées à des fins médico-légales. Reste le réel danger du piratage des données pour lequel aucune parade n’a pour l’instant été trouvé.
Les événements tragiques qui viennent de se dérouler en Israël mais également en Ukraine remettent en lumière la difficulté extrême d’identifier les victimes de catastrophes de masse. Pour faciliter ces procédures complexes mais nécessaires, INTERPOL a mis en place le protocole IVC, aujourd’hui internationalement reconnu.
Répondre le plus rapidement possible aux proches plongés dans une attente insoutenable tout en gardant une stricte approche scientifique est une gageure à laquelle sont confrontées toutes les équipes dépêchées sur les lieux d’une catastrophe ! Rédigé pour la première fois en 1984 et remis à jour tous les cinq ans, le guide IVC d’Interpol (Identification des Victimes de Catastrophes, DVI ou Disaster Victim Identification dans sa version anglaise) propose aux unités sur le terrain une procédure qui permet une identification formelle.
Un protocole en 4 étapes
Mis en pratique en 2004 lors du tsunami en Thaïlande puis de façon systématique lors de chaque catastrophe, qu’il s’agisse d’un événement naturel, d’un accident ou d’un attentat comme celui perpétré par le Hamas en Israël ces derniers jours, le protocole comprend quatre étapes complémentaires afin de ne laisser aucune place à l’erreur :
–L’examen des lieux de la catastrophe afin de procéder au relevage des corps mais également de tous les objets personnels,
–Le recueil de preuves médico-légales ou données post-mortem: relevé d’empreintes digitales et examen dentaire lorsque l’état de la dépouille le permet, prélèvements ADN (superficiels ou profonds), recherche de particularités physiques (tatouages, cicatrices, taches de naissance…), examen radiologique (recherche de prothèse, implants, broches, etc.).
–La consultation de données ante-mortem : il s’agit des dossiers médicaux existants ou de données recueillies par les équipes à l’issue de l’ouverture d’une fiche “Interpol – Personne disparue”. Dans ce cas, il va s’agir de récupérer l’ADN de la personne disparue via un object qu’elle a l’habitude de manipuler (brosse à dents, à cheveux, rasoirs) ou de le déterminer à l’aide de probabilités en récupérant l’ADN de personnes apparentées (parents, enfants, cousins, grands-parents, etc). Enfin, les experts de la gendarmerie nationale ou de la police nationale pourront également récupérer les empreintes digitales de la personne disparue soit dans un fichier soit sur un objet dont elle est la seule à manipuler.
-La confrontation des différentes données post-mortem et ante-mortem afin de pouvoir réaliser des rapprochements et grâce à une analyse approfondie par les experts, de procéder à une identification formelle d’une victime. Dès lors que l’identification est établie, le certificat de décès est délivré et les familles peuvent désormais récupérer le corps de leur proche et entamer ce long et douloureux processus de deuil.
Une expertise de pointe au chevet des morts
L’efficacité de cette intervention est intimement liée à la conjugaison de plusieurs expertises. En dehors de la police scientifique spécialisée dans les scènes de crime et des unités d’enquête, des experts en médecine légale, odontologie médico-légale, des anthropologues, des biologistes et des experts en empreintes digitales travaillent en concertation avant de rendre leurs conclusions.
La France qui a été régulièrement confrontée à ces situations dramatiques ces dernières décennies, s’est dotée d’unités de pointe : l’UPIVC (Unité de Police d’Identification des Victimes de catastrophes) qui est intervenue notamment lors des attentats du 13 novembre 2015 et dont la mise en œuvre est confiée au Service National de Police Scientifique (SNPS) et l’UGIVC (Unité de Gendarmerie d’identification des Victimes de Catastrophes) dont la mise en oeuvre est confiée à l’Institut de Recherche Criminelle de la Gendarmerie Nationale (IRCGN). Ces services spécifiques se déploient rapidement sur les lieux d’une catastrophe majeure, qui est dite « fermée « (lorsqu’elle concerne un groupe de personnes précis et identifiable comme lors d’un crash d’avion) ou «ouverte» (lorsqu’il est difficile de connaître le nombre de victimes comme lors de l’attentat de Nice en 2016).
Lorsque l’intervention d’une seule unité ne suffit pas, l’Unité Nationale d’Identification des Victimes de Catastrophes (UNIVC) prend temporairement le relais en activant conjointement les deux unités précédentes.
Des scientifiques de l’université d’Austin au Texas ont mis au point un décodeur capable de retranscrire les pensées d’une personne avec une précision qui frise la perfection. Pour quelles applications dans le futur ?
Quand informatique et neurosciences s’associent, cela donne naissance à une innovation technologique majeure qui risque de révolutionner la vie humaine. Dans une précédente étude, les universitaires de Zurich mettaient en évidence la possibilité de capter en moins de deux minutes l’empreinte d’un cerveau permettant d’identifier un individu avec une précision proche des 100% (voir article).
Cette fois-ci, les chercheurs américains ont utilisé deux technologies de pointe, un appareil IRM (Imagerie par Résonance Magnétique) et un modèle d’IA (Intelligence Artificielle) de type transformateur afin de décoder l’activité cérébrale et de la retranscrire en langage texte, tout cela de manière non invasive contrairement aux précédentes interfaces cerveau-machine qui exigeaient l’implantation d’électrodes par la chirurgie.
L’activité cérébrale passée au crible
Pour obtenir ce résultat, les scientifiques ont placé trois volontaires dans un appareil d’imagerie médicale et leur ont fait écouter des podcasts racontant des histoires. Pendant 16 heures, ils ont enregistré leur activité cérébrale et observé comment les mots et les idées générées par l’écoute de ces récits activaient les différentes régions du cerveau. Toutes ces données ont ensuite été passées au crible d’un système neuronal artificiel afin de les convertir en langage texte. Les tests, menés cette fois en faisant écouter de nouvelles histoires, ont permis de constater que le réseau décodait sans problèmes ces nouvelles pensées.
A terme, ce nouveau dispositif à visée médicale a pour but de permettre aux personnes lourdement handicapées, qui ont perdu l’usage de la parole et qui ne peuvent pas utiliser un clavier, de communiquer avec leur entourage par le simple fait de la pensée. Même si cette technologie reste perfectible, elle semble particulièrement prometteuse dans la mesure où selon l’un des chercheurs à l’origine de ce procédé, le décodeur IA peut déjà saisir l’essentiel d’une pensée parfois complexe et la retranscrire. En un mot, aller plus loin que les simples paroles…
Dans la tête d’un suspect …
Si l’étude suscite l’intérêt de tous les chercheurs en neurosciences, elle soulève également de nombreuses questions éthiques. Entrer dans la tête d’une personne pour fouiller dans ses pensées contre sa volonté pourrait à l’avenir devenir une réalité. On peut ainsi imaginer que dans le cadre d’une enquête judiciaire où le suspect reste muet et la victime introuvable, les policiers puissent obtenir des réponses et lever une fois pour toute le mystère de certaines disparitions. Et si cette machine avait pu faire « avouer » au cerveau malade de Michel Fourniret le lieu où est enterré le corps de la petite Estelle Mouzin ? Et si dans l’affaire de la disparition de Delphine Jubillar, cela permettait d’incriminer ou au contraire de disculper définitivement son mari actuellement en détention provisoire ? Autant de « si » qui plaident en faveur de ce procédé. A contrario, il peut également se transformer en arme redoutable pour museler la liberté de pensée, une tentation toujours possible dans certains pays pour qui la démocratie n’est pas une priorité.
Un risque qui n’existe pas selon les chercheurs à l’origine de l’étude. En effet, le décodeur ne fonctionne que sur le cerveau d’un sujet qui est entraîné et consentant. Dans le cas contraire, il lui est très facile de mettre en place des tactiques qui vont « saboter » les résultats. En bref, le cerveau humain gagne sur la machine. Pour l’instant…
Les policiers en rêvaient, le Ministre de la justice l’a fait ! L’article 3 de la loi d’orientation de la justice prévoyant la possibilité de prendre le contrôle à distance de la caméra et du micro d’un appareil connecté a en effet été adopté par le Sénat le 7 juin dernier. Une possibilité strictement encadrée et limitée aux affaires les plus graves comme le grand banditisme et le terrorisme.
Le bon vieux micro caché par un homme de l’ombre dans un pied de lampe ou sous le tableau de bord d’une voiture, a du plomb dans l’aile ! Grâce à cette disposition prévue dans le projet de loi justice du ministre Eric Dupont Moretti, les forces de l’ordre auront désormais la possibilité d’activer à distance un micro ou une caméra. L’objectif est double : obtenir la géolocalisation en temps réel et, dans le cadre d’affaires de terrorisme, de délinquance et de criminalité organisées, être autorisées à capter tous les sons et les images à l’insu de leurs propriétaires. Un gain de temps et d’efficacité inestimables pour les enquêteurs qui n’auront plus besoin d’identifier les lieux ou les véhicules et de se déplacer pour poser leurs mouchards avec le risque toujours possible d’être découverts.
Des limites bien établies
Ce qui est vrai pour un téléphone l’est également pour tout appareil connecté, enceinte, ordinateur, électronique embarquée, montre, qui pourra ainsi être piraté et espionné. Le début d’une « surenchère sécuritaire » comme s’en émeut notamment l’OLN (Observatoire des Libertés et du Numérique) ? Ce déclenchement à distance qui ne concerne évidemment pas « monsieur tout le monde » mais cible bien des individus identifiés par les policiers dans certains dossiers, sera soumis à un contrôle strict et devra notamment être validé par un magistrat. Le Sénat a par ailleurs adopté un amendement limitant le recours à la géolocalisation aux infractions punies d’au moins dix ans de prison au lieu des cinq ans initialement prévus. Il n’en demeure pas moins que l’accès à ces dispositifs d’espionnage vont dans le sens d’une surveillance de plus en plus généralisée, une source d’inquiétude pour certaines professions « sensibles » comme les avocats et les journalistes.
Des messages piégés
Pour les messageries comme WhatsApp et Telegram dont le système chiffré plus complexe offre une protection supplémentaire face à cette prise de contrôle, la seule manière d’y accéder passe par l’envoi d’un message incitant à cliquer sur un lien ou une pièce jointe qui va installer un logiciel espion. Une pratique déjà couramment utilisée par des individus malveillants pour dérober des informations confidentielles comme l’identité et les coordonnées bancaires de la personne victime du piratage.
Sources : Justice: Caméras ou micros des téléphones pourront bien être activés à distance (20minutes.fr) Le Sénat donne son accord à l’activation à distance des caméras et micros des téléphones (msn.com)
