Will this technique be that of the outcome of the Grégory affair, one of the most enigmatic French criminal cases? On January 27, 2021, the courts gave the green light for new DNA expertise in the Grégory Villemin case, in particular the DNA of relatives.

Because in this file opened more than 36 years ago, “there are still DNA profiles to be exploited (…) to discover the truth“assured the lawyer for Grégory’s parents, Me François Saint-Pierre. But what does this technique consist of?

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Linking two DNAs from the same family

The research of “DNA of kin”, which the experts are preparing to launch, consist in comparing a DNA with those of the National Automated File of the genetic fingerprints (FNAEG).

The DNA traces taken in connection with this case do not match any known DNA from this file. But they can look like one of them. This method will make it possible to link the suspect DNA to DNA from the same family and potentially appearing in the FNAEG.

The example of the Élodie Kulik affair

The “kinship” method has made it possible to resolve several cases in recent years, in particular the Élodie Kulik file, raped and murdered in 2002. The DNA found at the crime scene did not correspond to any profile referenced in Fnaeg and to any sample taken from several suspects. But in the Fnaeg appeared a man, whose DNA profile was genetically close to that of the murderer: it was his father, already on file because he himself was in prison.

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In the Gregory case, this method will be used to try to find “family” matches to nine traces of DNA taken from anonymous mail, from a syringe and from the child’s clothes.

Several months of analysis

In parallel, the justice also accepted the DNA sampling of 37 people more or less close to Grégory to compare them with different genetic profiles, according to Me Saint-Pierre.

The previous genetic expertise carried out in this case had given nothing. But the parents of Grégory, found dead at the age of four, in 1984, in the waters of La Vologne, still rely on scientific progress to elucidate this affair. However, the results of all these genetic analyzes should take several months, according to their lawyers.