Fans of detective series are used to it. As soon as a corpse is discovered, the police secure the crime scene to prevent it from being “polluted”, before the arrival of “the scientist”, a colloquial name given to experts dressed in full white coveralls who, armed small sachets and swabs, take a whole bunch of samples before analyzing them and contributing, often largely, to the resolution of the investigation.
But, in real life, does a paint chip really help to find the make and year of the car that had an accident? Can a hair, through the DNA it contains, convict a murderer?
To answer, the program “Science grand format” innovates and chooses to reconstitute in detail a news item, in order to show, concretely, the importance and the diversity of the work of the scientists of the Criminal Research Institute of the National Gendarmerie ( IRCGN). And it’s a total success: the viewer finds himself in the position of the investigator who, over the sometimes contradictory information that reaches him, tries to flush out the killer. With the added attraction that they are real facts.
Different trades
The textbook case studied here is the case of Christelle Dubuisson, found dead in a field, near Villers-Bretonneux, in the Somme, on August 21, 2002. The case was chosen for its exemplary nature, the work of the scientist for three years having been decisive. Twenty years later, the crime scene was reconstructed identically. Gendarmes and scientists today have agreed to repeat the same gestures as at the time, in front of the camera. First observation: the members of “the scientist” arrive well in white jumpsuits, but they wear two pairs of blue gloves…
To these reconstructed scenes are added the testimonies of investigators of the time, such as Jean-Louis Cauvet, director of the Dubuisson investigation unit (2002-2005), and Patrick Chilliard, IRCGN expert on this case. And the main thing: the follow-up, on site or in the laboratory, of the interventions of various trades, whose names were sometimes unknown.
If the profession of forensic scientist is known (Amandine Lamy details, among other things, the mechanism of rigor mortis), others are less so: crime scene coordinator; fiber expert; Head of Signal, Image, Speech Department; morphoanalyst… Unsavory but essential, the study of fly eggs taken from the corner of the victim’s eye is described by Hubert Joulin, head of the forensic entomology department, to refine the time of death.
Technological evolution
The viewer will note some differences with the fiction, such as the long time needed to obtain the analysis results – twelve hours to pass a card holder to the fumigation, in order to detect possible fingerprints.
The thoroughness of the search can also be gauged by a few numbers: the victim’s vest was cut into 506 fragments; 139 seals were analyzed over fourteen months to find five DNA; in three years, 1,507 seals were examined.
Another interesting reading angle: the technological evolution in two decades, with drones, scanners of the victims, GPS… presented according to what they could have brought to the case. Before the final ordeal of the trial, where anything can happen.
