When experts go astray: denial of justice for Michael Lognonne

On January 26, 2019, the Yellow vest protester Michael Lognonne was injured in the leg during the same incident that resulted in the loss of fellow protester Jérôme Rodrigues’ eye. Six years after the events, Lognonne’s complaint ended with a dismissal. The experts commissioned by the court claim he was injured by an unidentified LBD (Flashball) shot. However, Index’s counter-investigation establishes that Michael Lognonne was injured by the same grenade that blinded Jérôme Rodrigues, revealing how an erroneous expert opinion led the justice system into a dead-end.

The ruling of the Paris Court of Appeal, issued on January 24, 2025, brought an end to an investigation that lasted six years. In the case of Jérôme Rodrigues, the judges referred officer Brice C. to a criminal court to be judged for “voluntary violence causing mutilation”. On January 26, 2019, during Act XI of the Yellow vest protests at Place de la Bastille, this officer from the Compagnies de Sécurisation et d’Intervention (CSI) had launched an anti-crowd grenade (grenade de désencerclement, GMD) into a group of protesters gathered under the July Column, in the center of Bastille Square. One of the 18 projectiles ejected by the grenade hit Jérôme Rodrigues in the face, causing the permanent loss of his right eye.

In the same ruling, the Court of Appeal dismissed the case concerning the injury sustained by a second protester, Michael Lognonne, who had also filed a complaint. While standing right next to Jérôme Rodrigues at the moment of the grenade explosion, several videos of the scene show him collapsing to the ground shortly afterward. Injured in the right leg, he said to Index in March 2025: “I still have problems with my wound, it makes me limp, it bleeds… I’m 45 years old and I limp; what will I do when I’m 75?”

To determine the origin of Michael Lognonne’s injury, the judges in charge of the investigation ordered a medico-ballistic analysis. Based on their interpretation of the marks on his leg, the experts thus commissioned by the judges concluded that “only the 40mm LBD (a kind of heavy rubber bullet firing weapon also known as “flashball”, editor’s note) could cause an injury with the observed appearance.” However, since they could not identify such an LBD shot, the same experts, joined by a third, argued that “the images did not allow them to explain when and how Michael Lognonne was injured.” Due to the lack of evidence, the judges issued a dismissal.

Upon the announcement of this decision, Index, which had already produced a detailed reconstruction of the circumstances surrounding Jérôme Rodrigues’ injury, re-examined the available videos. Contrary to the conclusions of the judicial experts, our counter-investigation, presented in the video above, clearly establishes the circumstances of Michael Lognonne’s injury.

A single possible cause of injury

The available footage shows that Michael Lognonne was about two meters away from the GMD grenade launched by officer Brice C. at the moment it exploded.

A GMD grenade contains 18 rubber projectiles which, upon detonation, are ejected in all directions at a speed between 400 and 500 km/h. Anyone within a 15-meter radius of the explosion can be violently impacted by these projectiles. Michael Lognonne’s position is therefore fully compatible with an injury caused by this grenade.

A second later, an LBD shot was fired by officer Baptiste R. This shot is visible from multiple angles in the available videos. Based on these images, Index conducted a 3D modeling of the scene, integrating the position of the shooter and the orientation of his weapon’s barrel at the moment of the shot. This reconstruction confirms that the trajectory of the projectile passed well to the side of the group where Michael Lognonne was. Therefore, Baptiste R.’s LBD shot cannot have caused his injury.

The hypothesis of another LBD shot was raised during the judicial procedure. However, an audio and video analysis of all available sources clearly establishes that only one LBD shot occurred in the vicinity during the period when Michael Lognonne was injured: the shot fired by Baptiste R., which, as established earlier, could not have hit him.

Between the moment when Michael Lognonne is seen still standing and the moment when he collapses, only one event that could have caused his injury occurs: the explosion of a GMD grenade at his feet. Therefore, we can affirm that Michael Lognonne was injured by the same grenade that mutilated Jérôme Rodrigues, launched by officer Brice C.

An “ultimately established” erroneous, expert-fostered conclusion

Our counter-investigation also highlights flaws in the judicial procedure concerning Michael Lognonne’s case, which gave major weight to expert reports whose methodological rigor is questionable.

The medico-ballistic expert report

In January 2020, a first “forensic and ballistic expert report” was submitted to the investigating judges in the Rodrigues/Lognonne case. It was signed by expert Pierre Laurent – who is regularly appointed in cases of police violence that we have studied – and Dr. Frank Questel, an expert in “forensic medicine, toxicology, and bodily injury.” In this report, the experts confidently state that Michael Lognonne’s injury was caused by an LBD shot. They categorically exclude the possibility that it was caused by the explosion of a GMD grenade, despite numerous pieces of evidence pointing toward this hypothesis, such as videos, testimonies, and medical examinations.

To justify their opinion, the experts rely on an examination of Michael Lognonne’s injury at the hospital on September 20, 2019 – nearly seven months after the events.

The experts wrote in their medico-ballistic summary:

Case evidence and videos confirm that at the time Mr. Lognonne and Mr. Rodrigues were injured, a GMD grenade had been launched in their direction and a 40mm LBD shot was fired one second after the grenade exploded, still in their direction.

One major error, crucial given their assigned task, is identifiable here. Based on a superficial observation of the available videos, the experts assumed that the LBD shot fired by Baptiste R., mentioned earlier in our counter-investigation, was directed at the group of Michael Lognonne and Jérôme Rodrigues. However, the 3D reconstruction clearly shows that the shot was not aimed at this group and could not have hit Michael Lognonne.

To illustrate their analysis, the experts provided the following reconstruction diagram, where the LBD shot is incorrectly shown as directed at the group of protesters. This diagram can be compared with a top-down view of the 3D reconstruction of the moment of the shot, which Index produced by cross-referencing all available images of the incident.

In the summary of the medico-ballistic report, the experts write:

Of these two weapons, only the 40mm LBD was likely to cause an injury with the observed appearance. Indeed, the size and “ring-like” aspect of the scar is typical of a non-penetrating impact from a soft, high-energy projectile of large diameter, namely (…) a 40mm LBD projectile. An impact from a GMD pellet would have left a smaller mark without the “ring-like” aspect.

By observing solely the shape of the injury — interpreted as having a “ring-like” appearance — the experts conclude which weapon caused it. To justify their conclusion, they rely on a questionable formal interpretation and present an erroneous argument.

Regarding the shape of the injury, the experts ignored the medical opinion of Dr. Lormeau from the Paris medico-judicial unit, who, after examining Michael Lognonne on February 12, 2019, 17 days after the incident, described the injury in these terms in his medical certificate:

“On the anterior face of the middle part of the leg, a horizontal wound in the process of healing with a fibrinous base of 1.7 cm × 0.7 cm, topped by a healed erythematous rectangular wound of 2.5 cm along the long axis.“

Commenting on a photograph of the injury taken the day after the incident presented by Mr. Lognonne, Dr. Lormeau described it as “a contused wound, roughly rectangular in shape.”

A GMD grenade pellet has a rectangular shape with rounded edges, measuring 2.8 × 2.2 cm. Its shape and dimensions are therefore entirely compatible with “a wound […] of a rectangular shape with a 2.5 cm long axis,” as observed by a doctor in a medical certificate included in the judicial file of the case, and even cited—though ignored—in the expert report by Mr. Pierre Laurent and Mr. Franck Questel.

Furthermore, we compared the experts’ claim that “an impact from a GMD pellet would have left a mark of smaller size and without the ‘ring-like’ aspect” with a sample of images of injuries caused by a GMD grenade, extracted from the database of the site violencespolicieres.fr. These images show a wide variety of injuries, several of which appear circular in shape. Some of these injuries and marks on the skin are equal to or larger in size than that of Michael Lognonne. These examples therefore contradict the experts’ statement regarding the size and characteristic shape of injuries caused by GMD grenades.

⚠️ Warning: graphic images (injuries, blood)

To further investigate this issue, Index sought the opinion of two other doctors, Dr. Abdelrani Bourazi and Dr. Marie Nemon, who documented their analysis in a medical certificate. According to them, based solely on the observation of Michael Lognonne’s injury, “it is impossible to rule out the hypothesis that the injury was caused by a GMD”.

Given all the elements that contradict it, it appears that the authors of the medico-legal and ballistic report, Mr. Pierre Laurent and Mr. Frank Questel, made an error in their expertise: in no way does the appearance of the injury allow for the conclusion that Michael Lognonne was injured by a 40mm LBD projectile.

The forensic expert report

In April 2022, the judge in charge of the investigation appointed Mr. Philippe Esperança, a forensic expert, to analyze the available videos of the incident and “create a 3D model of the sequence of events.” The expert submitted his report in July 2022.

Regarding the LBD shot fired by Baptiste R., the 3D reconstruction produced by Mr. Esperança aligns with that created by Index. At the end of his report, the expert concludes that “the LBD shot does not seem to have hit either of the two victims” and that “the launch of the GMD is the cause of Mr. Jérôme RODRIGUES’ injury and most likely Mr. Michael LOGNONNE’s injury.”

In light of the discrepancies observed in the conclusions of the expert reports submitted in the case, the judges in charge of the investigation ordered the authors of the medico-ballistic report and the author of the forensic report to produce a “complementary collective summary (…) in order for them to compare their reasoning and conclusions.”

The collective summary expert report

In their collective report, submitted on June 15, 2023, the experts who authored the medico-ballistic report persisted in confirming that Michael Lognonne’s injury was caused by a 40 mm LBD shot, and that the GMD grenade could not have been the source of this injury.

The forensic expert also maintained his conclusion regarding the LBD shot fired by Baptiste R., stating that it could not have hit Michael Lognonne due to its direction and the position of the shooter. The expert also noted that at the time of the shot, colleagues of Baptiste R. were positioned between him and Michael Lognonne, a point also confirmed by the 3D reconstruction produced by Index.

As the mission to resolve the contradiction between the previous expert reports was unsuccessful, the collective summary concludes with a lack of conclusion, with the investigating judges noting that “the analysed images did not allow for establishing when and how Michael Lognonne was injured in the leg.”

The dismissal ruling

In their ruling of dismissal regarding the charges related to the injury sustained by Michael Lognonne, the judges once again refer to the first medico-legal and ballistic report, stating that “it is ultimately established that Michael Lognonne was struck on the right tibia by a LBD shot.”

The judges also upheld the conclusions of the criminalistics expert as “definitive”: the trajectory of the LBD shot fired by Baptiste R. was not directed at Michael Lognonne and therefore could not have hit him.

Having been unable to establish the circumstances under which Michael Lognonne was injured, this procedure, which lasted six years and involved three experts and as many reports, ultimately led to the abandonment of charges for “violence with a weapon exercised by a public officer” that caused Michael Lognonne’s injury. The judges concluded: “There is no grounds to pursue [officer Baptiste R.] or anyone else on this charge.”

Index’s counter-expertise establishes that Michael Lognonne was indeed injured by the same GMD grenade that mutilated Jérôme Rodrigues – this grenade being not only the most plausible cause but also the only possible cause of his injury.

It also identified the medico-ballistic report’s error that led the judicial procedure into a deadlock: the claim by experts Mr. Pierre Laurent and Mr. Franck Questel that the shape of the injury categorically excludes the possibility that it was caused by a grenade designed for crowd control is based on nothing but an argument of authority. This claim is contradicted by several comparable documented injuries as well as the opinions of two other doctors. In the interest of truth, Index publishes its findings from the independent counter-expertise, so that justice can take it into account.

Lastly, it is important to address the fact that a single throw of a crowd control grenade into a group of protesters caused two individuals to suffer permanent injuries, even though neither of them was held responsible for any offense. This observation once again highlights the inherent danger of these weapons, which remain officially classified as “war ordnance” (matériel de guerre). Despite the dozens of individuals documented as having been seriously injured by crowd control grenades, these weapons are still part of the arsenal of law enforcement in France, which regularly employs it, even outside of crowd control contexts.

Team