The Gendarmerie Forensic Institute Model (English Version)

  • Par Contributeur 411117
  • Publié le 04 mars 2019, mis à jour le 13 juin 2023

Colonel Patrick Touron1(Msc), Lieutenant Marianne MALO²(Msc)

1 : Director of the Institut de recherche Criminelle de la Gendarmerie Nationale,

2 : Deputy chief of the Fingerprints unit.

 version française disponible en PDF en fin d'article.


In the past, confession and testimonies were sufficient to convince magistrates and jury's members. Nowadays, scientific evidence has become a basic element for criminal investigations. Regards of this evolution, the gendarmerie has created a “criminalistic chain” based on criminal investigations specialists in charge of collecting samples from crime scenes. A specific unit dedicated to the analysis of these samples has been created in 1987 and named Gendarmerie Forensic Institute (IRCGN : Institut de Recherche Criminelle de la Gendarmerie Nationale).

Competence is a fundamental requirement to produce reliable products. The great diversity of the scientific and technical specialities in the Institute requires a highly individualized recruitment amongst the candidates who have not only to account of exclusive skills but also of a great interest in the forensic police field. The competence of officers is tested regularly under ISO 17025 accreditation norm, together with the validity of the method used, particularly in the interpretation of the results. For forensic Institutes the core products comprise – among others- the collection of evidence at the crime/incident scene, analysis of seized material, interpretation of the analytical results or other findings and expert reports where the activities and findings are summarized and evaluated.

Forensics – expertise – National Gendarmerie – justice – management – organization

science forensique

science forensique

I – Introduction

The IRCGN is a forensic science institute which has been devised according to the French gendarmerie organization environment, where forensic examinations are carried out, and applied or experimental research works are conducted [1]. The Institute is a unique model for several reasons. First, the multidisciplinary areas of expertise are all concentrated in one place. Second, the Institute is able to send forensic expert gendarmes, anywhere in the world, in a few hours. Third, the Institute can strengthen Gendarmerie’s operational teams [2] or be joined by other specialized gendarmes.

Its creation is due to the observation that there was a lack of means to exploit crime scene evidence [3]. The IRCGN has progressively built its identity under the labels of its scientific rigor, its reliable results through its quality assurance process [4], its ability to provide an appropriate and strong operational support, and its innovation and creativity powers. IRCGN forensic scientists all hold confidential or secret defense clearances. It allows them to conduct classified scientific investigations for national security reasons. Forensic scientists have been needed for a long time [5] at the criminal trial because they can broaden the debate by demonstrating or explaining the results of their analysis. 

Forensic sciences combine all the sciences requested to exploit the pieces of evidence from the crime scene. The results will then enlighten the relevant jurisdiction. It is important to differentiate between the search for a scientific truth close from an unsure reality, and the court decision which is the judicial truth. The scientific methods used for forensic examinations should have a sound theoretical basis, be rebuttable, be published, have a stated uncertainty and not be dogmatic.

At a standard crime scene, specialized investigators are called after the event occurred. They are going to process to the collection of exhibits, to the swabbing and sampling of the crime scene in order to reconstruct the circumstances of the crime. This approach – including the use of observations to infer the effects that are at their origin, is complex [6]. Crime scene investigators conduct a full forensic examination. Before any modification, they freeze the crime scene in order to preserve it. Then, they carry out specific sampling according to standardized processes, ensure the preservation of the samples in a suitable packaging. After that, they request gendarmerie forensic support centers, private or public specialized laboratories for the samples’ analyzes. The scientific results must be put into proper context, regarding other aspects of the investigation or other elements from the scene [7]. By definition, sciences are constantly changing. It is therefore essential to update knowledge and skills of expert assessment, and to always be innovative, so as not to fall behind nor to mislead the final user of the results that is justice. Forensic sciences abide by the same rules and the IRCGN permanently train its staff. In addition, thanks to the proximity with the gendarmerie criminal identification technicians (TIC), the institute develops innovations [8].


II – The creation of an independent structure within the gendarmerie

The 80s mark a turning point in criminal investigation in France, with the belated – as compared to Anglo-Saxon world – discovery of the need to scientifically use any piece of evidence. A holistic and scientific exploitation of the scene has become necessary since the investigators and the magistrates wanted to understand what occurred and identify all the participants, without depending on fragile or changing testimonies. An opposition is too often made between confession and scientific evidence. It shows a lack of knowledge about the search for the truth throughout criminal investigations. Indeed, these two aspects, brought by different players in the investigation, depend on one another to get closer to the truth. Confession and scientific evidence should not be considered as rival but as complementary.

         2.1 – Diagnosis

The French gendarmerie coped with difficult issues coming from structural origin such as a lack of specialized staff to help investigators [9]. Indeed, a lack of technical expertise is noticed among investigators during the detection process. The 7-point approach (hearing and confronting testimonies, preserving the crime scene, methodically searching for physical evidence, collecting them with appropriate tools, preserving them until the delivery to the laboratory, analyzing them taking into account the collection environment, and finally being able to conclude about the information provided by the evidence) that appears so natural nowadays is ultimately quite recent.

At that time, the Gendarmerie decides to undertake needed reforms. Since then, new relevant specialized units have been created, while preserving the Gendarmerie culture and identity. The Gendarmerie has adapted its new tools to its organization, requiring to be available to anyone, anywhere, at any time, to be able to join any Gendarmerie unit working within the 7-point approach defined above.


        2.2 – A man-based structure

It started in 1987 with the creation of the Criminal Investigation Technical Section (STIC), leading to the birth in 1991 of the Gendarmerie Forensic Institute (IRCGN).

The IRCGN receives different missions ranging from analyzing physical evidence, being deployable, teaching investigators about sample collection and doing applied research. In order to generate synergies and coordinate forensic science chain with intelligence chain, the Judiciary Center of the Gendarmerie Nationale (PJGN) [10] has been created in 2012. It combines the IRCGN and the Criminal Intelligence Central Service (SCRC). The need of specialized investigators with specific technical and judicial skills has led to the creation of more focused offices.

This organization requires high skilled scientists that the Gendarmerie can find among its officers, or non-comissionned officers or within French Defence Health Service (SSA). A recruitment campaign has also been launched in the fields of forensic sciences: chemistry, computer sciences, biology, anthropology. Indeed, the Gendarmerie as a military force can be joined on the basis of qualifications, with a competitive selection process among candidates with an Engineering Degree or a Master’s Degree.

At the moment, about 230 scientists work at the Institute. A quarter of them owns a PhD, a third of them owns a Master’s or an Engineering Degree, and the others have a Bachelor’s Degree.

Once selected, the scientific officers intended for serving in the Gendarmerie, undergo through military and professional training at the French Gendarmerie Officers Academy (EOGN). Then, they start their carrier as apprentices in a unit matching their area of competence. They become expert after the completion of a research work in the field, about three years after their posting. During the next seven years, they undertake expertise in their unit. Then, they take the command of a gendarmerie company (county level) so as to better evaluate investigators' needs. After four years of operational activities, they may come back to command a department. Thus, scientific officers switch between very technical and operational positions.

         2.3 – The forensic chain

Forensic science activities (the analysis of common pieces of evidence) and legal data reconciliation (information about facts and way of operating) operate at three different levels.

Local criminal investigation technicians (TICP) of the territorial brigades detect, collect and ensure transportation of pieces of evidence linked to localized crimes (burglaries, car thefts, incivilities…). They cover all the cantons of the national territory. As regards to the county level, forensic sciences are performed by criminal investigation technicians (TIC) in a forensic platform using standardized processes. They deal with more serious offenses and can be supported by new technologies specialists (N’Tech) or by forgeries experts (EFD).

In the 80s, a central structure was needed. Historically, France has 5 laboratories belonging to the National Police, the Central Laboratory of the Police Prefecture, and other private laboratories. The Gendarmerie has been able to offer a global answer to investigators’ needs, to operational work and to citizens’ expectations.


III – The IRCGN construction

The IRCGN is built around four major axes:

- the ability to conduct scientific investigation or expertise for investigators or magistrates ;

- the ability to deploy forensic experts on the field and give support to investigators ;

- the ability to ensure a high level formation to the entire staff of the forensic chain ;

- the ability to ensure a follow-up of the innovations or carry out research [11] or experimental projects.

IRCGN experts do not investigate and must retain absolute professional independence from the referring source requesting the evaluation. Therefore, working at the IRCGN means losing their competency of officer of the criminal investigation (OPJ) [12].

The need of skills has shaped the IRCGN structure. 16 scientific units are split into expertise groups depending on the need (for instance, the “fire, explosives and environment unit” is split into three fields, for optimization purpose). Four units are gathered into one specialized department: Forensic Physics and Chemistry Department, Forensic Engineering and Digital Department, Forensic Human Identification Department, and Forensic Genetic Biology Department. The IRCGN also built up two deployable units able to deal with complex scenes. Theses teams set up regarding the nature of the crime scene and are made of chosen experts from each IRCGN unit.

A quality assurance service strengthens the whole structure in order to guarantee the reliability of the results, through accreditation according to ISO CEI 17025 [13]. According to the IRCGN, a scientific result [14] is rebuttable, demonstrable, given with a measurement uncertainty that is known. It is also the result of a published technique,  recognized by the scientific community. Because we are working to uncover the truth, and we present the results to non-experts, we have to be clear and understandable not to mislead magistrates. Explaining results in court is a fundamental part of the expert’s job.

Thus, French Gendarmerie owns:

- a strong expertise across the whole spectrum of forensic sciences ;

- deployable expert gendarmes who can bring scientific help to investigators.

For theses reasons, the IRCGN ranks as one of the best Forensic Science Institute.


        3.1 – IRCGN Organization

The IRCGN works only for benefit of justice and therefore only receives judicial seals. This process guarantees traceability of these exhibits, their provenance and their origin. The process is consistent with the procedures which are followed by the IRCGN. The IRCGN shares its know-how and its analytical databases such as the ones of automotive paints, drugs or arms with national Police services and the European forensic sciences laboratory network [15].

Regarding traceability and quality assurance, the single entry point for seals is the most reliable solution and has been adopted. The Front Desk is responsible for seals management, it checks on the legal compliance of requisitions, the good condition of the exhibit and their preservation.

The Quality Assurance Service checks and ensures quality standards, controls good practices in the field. This service sets up controls about experts’ qualifications, equipment, workplace environment and expertise processes. These actions guarantee the results' reliability. The QA Service is directly linked to the Director and therefore has some means to make necessary comments and controls.

The Data Interpretation Service (SID) offers a mathematical independent expertise to any IRCGN unit, in order to estimate the relative influence of some parameters in complex cases. The Bayesian approach [16] of the results helps to understand and deliver scientific results. It also couples a verbal scale with numbers depending on the area of expertise.


         3.2 – The Forensic Physics and Chemistry Department

This department deals with traditional features of forensic sciences. It has all the required devices and analytical tools to analyze natural or synthetic samples. The forensic experts working in this division are constantly adapting to new equipment with increasingly effective, specific and sensitive devices. Hence few nanograms or picograms of substances can be formally identified. This ability is essential when searching for flammable or explosive compounds.

Sample will be processed by specialists from the corresponding area of expertise depending on the type of crime scene encountered. Thus, Toxicology unit will be involved for poisoning cases whereas the Environment and Explosives unit will deal with the search for explosives residues. The experts work not only to identify compounds but also to explain their impacts and consequences or their origin. This data is essential for investigators who are seeking to find perpetrators or seeking incriminating evidence. Microanalysis unit depicts Locard’s Exchange Principle [17] by examining residues and traces in order to provide their origin and explain their presence.

Ballistics unit also belongs to this department even though it is not associated with an analytical activity. A strong mechanical expertise enables ballistics experts to explain how the firearm operates, to compare projectiles impacts or to identify a firearm or its hazardousness thanks to the remains collected on a crime scene or in a corpse. The unit has one of the largest collection of firearms in Europe, gathering 7000 types of long arms and 3000 types of handguns. This gun collection, coupled with an ammunition collection of more than a million projectiles allows the experts to work to the highest standards of precision and to reconstruct crime scenes in order to enlighten magistrates about the circumstances in which the gun was used. The experts are able to match a distorted projectile with a batch of ammunition thanks to lead isotopic analysis [18], or to date a shot with the analysis of the barrel’s residues [19].


          3.3 The Forensic Engineering and Digital Department

The Department concentrates the scientists dealing with signal and image processing, computing and electronics or with exhibits related to these subjects. The experts have several computers and are aware of the last developments in this evolving field. Accessing an encoded smartphone or a password protected computer are part of their missions when these elements are needed to materialize offenses or to establish links in the case serious offenses like pedopornography. Thus, forensic computer scientists work together with electronic engineers and cryptologists. Signal processing involves bringing a meaning to the collected digital information. It ranges from data analysis of a black box found in an aircraft crash to video image processing, through hard drive and phone processing. Document analysis fall within this category since they are more and more digital and require software tools to read them taking into consideration the numerous security devices. Document Unit uses optical macroscopes and spectroscopic analysis methods to detect fraud, spot counterfeit documents and establish links between these counterfeits.

Vehicle Unit belongs to this Department since the increase in computerization of vehicles. It now involves driving assistance systems developing towards delegate driving if not autonomous. This unit is dedicated to vehicle investigation in case of car accident, vehicle search in case of hit-and-run and vehicle identification. It is one of the specific features of the Institute. The unit daily shows the relevance of its missions as the vehicle is widely used as a means of transportation and as an information conveyor.


        3.4 – The Forensic Human Identification Department

This department is gathered around the elements enabling human identification. First of all, DNA identification is such a significant part of forensic activity that it required the creation of an entire Department (Forensic Genetic Biology Department, described below). Fingerprints identification has been known and performed for more than a century. It has not lost its relevance as it combines two criteria for an identification: uniqueness and persistence. Moreover, Fingerprints Unit uses revelation techniques which have sharpened and improved, facilitating identification of individuals present in the French AFIS (FAED). When the human body is at the state of a skeleton, Anthropology Unit is able to establish identification information such as age, sex or height or information about death circumstances and environment. The experts of this unit are coupled with the blood stain analysis specialists. They are the ones that better assess the violence of a bloody scene. The Forensic Pathology and Odontology Unit is another unit of the Department. It is made of odontologists who are able to analyze dentition and bitemarks, also leading to identification. When a mass fatality incident occurs, these experts are essential in the identification process, especially when corpses are seriously injured (fire, biological damage…). Forensic pathologists also try to establish crime circumstances. The last unit is the Forensic Fauna and Flora Unit. This unit, dealing with the crime scene ecology, is able to collect essential data about the place and date of the crime from the surrounding environment.


        3.5 – The Forensic Genetic Biology Department

This department is dedicated to the use of DNA. It is made of three units that proceed to biological analyzes under three different aspects. In each unit, samplings are normalized in order to allow a large-scale effective exploitation. The High Troughput DNA Unit for Individuals Samples (SCAGGEND–I) is in charge of analyzing swabs from people who are subject to criminal prosecutions which include DNA profiling for integration in the national DNA Database (FNAEG). All the DNA samples collected on crimes scenes come to High Troughput DNA Unit for Casework Samples(SCAGGEND–T) in charge of theses analyzes. The results are compared to the national DNA database to enable identification, in case of the offender’s DNA is known in the database. The Biology Unit only deals with samples that could not have been standardized and automated. The forensic biology experts are able to conduct deeper analyzes, adapted to the nature of the sample. The DNA Sample Conservation Central Service (SCPPB) keeps the DNA samples from which DNA profiles have been determined. Tens of thousands of samples are conserved in a controlled environment, for several tens of years, for the purpose of another possible analysis.


        3.6 – Identification and Investigation Department (UII)

This Department is devised with respect to the crime or catastrophic scenes where the IRCGN is involved. IRCGN experts not only have lab expertise skills but they also put these skills into practice. Thus, in the majority of forensic science fields, experts have developed tools or human skills to be deployed on field. The most emblematic unit is surely the Disaster Victim Identification Team (UGIVC). The team is deployed for natural or man-made disaster victim identification. Depending on the case, this unit is made of medical examiners, odontologists, DNA and fingerprints experts but also of explosives, fires or accidentology specialists. This unit has operated on more than 85 disasters for 25 years, on the national territory or abroad, when it dealt with French victims identification. The National Crime Scene Squad (UNIC) is involved in serious (often bloody) crime scenes. This unit sends equiped experts according to the crime scene.These two units are able to adapt to the forensic chain and to any gendarmerie support team.

IV – Conclusion

The IRCGN is a forensic science institute, built by the French Gendarmerie, able to exploit crime scene evidence. Any piece of evidence, anywhere in the world, in any environment, can be examined by IRCGN teams deployed in few hours. The institute is settled in Cergy-Pontoise with more than 20 000 m² devoted to laboratories. It meets the needs of investigators and magistrates in all the areas of forensic sciences, helping the establishment of truth and criminal trial. Each day, more than 500 cases are worked on. On average, one team is daily deployed on the national territory to support investigators to solve criminal cases. The 240 different testing methods demonstrate the multidisciplinary feature of the IRCGN. The institute is therefore able to innovate and create new performing tools, fully suited to the French Gendarmerie needs. Devices developed by the IRCGN are specific to the Gendarmerie’s range of actions. For instance, “Gendiag” helps investigators to detect counterfeit pieces, a wrapped or stolen vehicle in a matter of minutes. It works by plugging the device directly on the controlled vehicle. An other example is the new biological removal system named “Gendsag” which is included in the mobile DNA analysis laboratory “LabADN”. This technology provides the experts with someone’s DNA profile in less than 4 hours, on the crime scene. The Gendarmerie receives license fees from this patented system [20].

The IRCGN, financed by the French National Gendarmerie, is made of expert gendarmes who are completely independent. Human and material resources are at the disposal of the justice while searching for the truth in criminal investigations but also at the disposal of each French citizen anywhere in metropolitan France and French overseas territories. Our military culture brings us together and each expert knows that the cohesive group works for the same goal: searching for the truth for the benefit of justice.

modèle forensique Gendarmerie.pdf (1,8 MB)

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