🚨 HIGH-IMPACT CASE — PROVINCE OF BUENOS AIRES — MAY 18, 2026

The teenager was savagely assaulted by Leonardo Marcelino while lying wounded on a stretcher, under the passive gaze of police and health personnel. The aggressor is a fugitive and has a previous conviction for aggravated sexual abuse. The case, labeled as culpable homicide, could be reclassified. Chascomús demands justice.

📅  Tuesday, May 19, 2026   ⏱️  Reading Time: 6 minutes   📌  Chascomús, Buenos Aires, Argentina   ✍️  Research Writing

The Buenos Aires city of Chascomús was dismayed after a succession of events that ended the life of Kevin Martínez, a 15-year-old teenager with no criminal record. The day began with a traffic accident and escalated to become, according to his family and the lawyer who represents them, a homicide committed in full view of police and health personnel.

On Tuesday, May 13, Kevin was traveling as a passenger on a Honda XR 150 motorcycle driven by S.M., another 17-year-old boy, when both were hit on the corner of Jacarandá and Julián Quintana streets by a Ford Ka driven by María Antonella Saint Jean, a 25-year-old woman. The impact was violent and left the two minors seriously injured on the pavement.

The SAME personnel arrived at the scene and prioritized the care of S.M., whose condition was critical: he lost a leg due to his injuries. Kevin, on the other hand, remained immobilized on a stretcher on the public road, conscious, with a broken leg and visibly scared, waiting to be transferred.

It was at that moment of extreme vulnerability that the episode that has shaken all of Argentina occurred. Leonardo Marcelino, a merchant who lived a few meters from the corner of the accident, approached the injured teenager and began a brutal aggression. According to the case and can be seen in the images obtained by witnesses, the man repeatedly hit Kevin on the head with his fists, grabbed him by the neck and put a knee on his body.

It all happened while the minor was asking for help. In the videos that circulate, Kevin's voice is clearly heard begging for "help" and asking to be released, while some neighbors reproached the aggressor for his attitude. Police officers, municipal personnel and health workers were at the scene. However, no one intervened in time to stop the beating.

The reason alleged by Marcelino, according to hypotheses that circulated among neighbors and were picked up by media such as C5N, is that he accused the teenager of having stolen the motorcycle on which he was riding. However, Kevin's own family and the judicial investigation agree on a critical point: so far there is no element in the file that links the teenager to that robbery.

After the blows, Kevin was completely unconscious. It was then that he was finally put in the ambulance. The aggressor slowly withdrew before the eyes of those present and escaped from the scene. Since that moment, Leonardo Marcelino has remained a fugitive from justice and is intensely sought by the Buenos Aires police.

Kevin Martínez was transferred to the Franchín Sanatorium, in the Buenos Aires neighborhood of Almagro, where he agonized for two days. He died on Thursday, May 15. The preliminary autopsy established "polytrauma" and "internal bleeding" as the cause of death. Forensic sources consulted by Infobae pointed out that, so far, these injuries are compatible with the crash into the car.

However, the family and their lawyer refute that conclusion. The lawyer categorically stated that "there is no doubt that the cause of death is the blows" and that the scientific expertise in progress will be decisive. According to his words, the traffic accident "is very far from causing death" to the teenager.

A version that circulated on social networks and was picked up by C5N journalists indicates that Kevin would have suffered a collapse of the skull as a result of the blows. This hypothesis, if confirmed by an expert, would radically transform the cover of the case and the criminal responsibilities involved.

One of the most disturbing facts of the case is the judicial history of Leonardo Marcelino. The family's lawyer revealed to the press that Marcelino was recently sentenced by the Oral Criminal Court (TOC) No. 1 of Dolores to a sentence of between 12 and 15 years in prison for aggravated sexual abuse.

Despite this, Marcelino was free at the time of the event and, after committing the attack, he managed to escape. At the close of this edition, the Buenos Aires police are looking for him intensely. He is the only person that the Justice Department directly links to the beating, but he has not yet registered a formal charge for Kevin's death.

As shocking as the aggression itself is the conduct of the police officers present. The videos show that the agents observed how Marcelino beat the injured teenager without intervening with the speed that the case demanded. Kevin's father, Marcos, told the press: "I saw the video a thousand times and I can't find an explanation. The pain is so great that I don't understand why the justice system didn't act while there."

The mother, Romina, added: "There were officers and enough people to hold him and keep him from approaching." The family's lawyer announced that he will request that the "criminal responsibility" of the police officers and ambulance personnel who witnessed the attack be investigated. The Municipality of Chascomús acknowledged in a statement that "the actions of police personnel must be evaluated."

According to the lawyer, "there was a network of complicity regarding the definitive cause of death" and said that "if they had acted as they should, this would not have happened." He also questioned that Kevin had been handcuffed on the stretcher despite being seriously injured, describing such treatment as humiliating and unjustified.

Those who knew Kevin Martínez paint the portrait of a normal, lovable teenager without conflicts with the law. His grandmother, in dialogue with TN, described him as "a very companion" and "an excellent boy." His mother, Romina, declared that "he was beautiful, cheerful; all the noise around him was for joy" and added: "There are no words. I have no consolation. The only thing that keeps me going is knowing that we have to fight for justice."

Judicial sources consulted by Infobae confirmed that Kevin Martínez did not have any criminal record. The only connection with the stolen vehicle was circumstantial: he was traveling as a passenger on a motorcycle that had an active kidnapping order since May 9. It is unknown if the teenager knew that the motorcycle was stolen.

This Monday, May 18, at 4 p.m., family, friends, neighbors and citizens from all over the country who followed the case call for a peaceful march in Chascomús. The mobilization will depart from Misiones 81, the home of the Martínez family, and will go to the local police station.

•        Time: 4:00 p.m., Monday, May 18, 2026

•        Starting point: Misiones 81, Chascomús

•        Destination: local police station of Chascomús

•        Slogan: "We don't want violence, we want justice"

The judicial investigation was in charge of prosecutor Daniela María Bertoletti Tramuja, head of UFID No. 9 of Chascomús, who delegated police tasks to the local Departmental Subdelegation of Investigations. The only one formally charged so far is the driver of the Ford Ka, María Antonella Saint Jean, whose case is labeled as culpable homicide. He remained at the scene after the accident.

Leonardo Marcelino, the aggressor who escaped, has not yet been arrested or formally charged at the time of going to press, although the prosecutor's office is analyzing multiple accusations. The final results of the autopsy and the scientific expertise will be key to determining whether the cover escalates to intentional homicide and how many people – including police and health personnel – should be criminally liable.

The other teenager who was traveling on the motorcycle, S.M., 17, is still hospitalized in serious condition and had a leg amputated. Unlike Kevin, he does have a record for robbery.

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📰 Note prepared with information from Infobae, Minuto Uno, Ámbito , Crónica, La Noticia 1 and Diario Nuevo Día • Update: 18/05/2026

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