Introduction: The compressed air weapon is a type of arm to which the projectile is propelled due to the compression of air in a sealed chamber. These types of weapons belong to the category of non-lethal weapons and ammunition subject to authorization. However, accidental fatal cases, suicides or even deaths with intention attributed to these types of weapons are described in the literature. Case presentation: We are discussing the case of a 5-year-old boy who, at a picnic with several families, is shot and killed with a compressed air rifle, left unattended. The medical crew arrived at the scene could not save the boy’s life. Necroptic examination revealed a gunshot wound through the heart, with the projectile stuck in the lateral-internal wall of the right ventricle. The projectile identified was a metal type projectile (lead), with a length of 8.5 mm and a diameter of 4.5 mm. Conclusions: Compressed air weapons, although considered non-lethal, have proven over time their extremely dangerous potential through the fatal injuries produced. Raising public awareness, limiting use and enforcing strict legislation could prevent tragic events.