The debate over the lethality and ownership of modern, high-powered weapons has recently grabbed the headlines. High-velocity air weapons, advertised as starter guns for children, can cause lethal injuries despite non-lethal appearing wounds. Presented is a rare case of a modern, high-powered air weapon used in a homicide. A literature search yielded reports of only three previous murders by air weapon in the United States and only one involving injury to the thorax. In the current case, the killer used a diabolo pellet to penetrate the chest. The pathway tracked through the sternum, piercing the anterior pericardial sac and perforating the right ventricle, which led to a pericardial effusion. The pellet embolized to the left pulmonary artery and eventually the vasculature of the left lung. Cause of death was a penetrating gunshot wound of the chest most likely leading to cardiac tamponade. This case exemplifies several important characteristics of penetrating chest trauma from air guns: first, air rifles, with exit velocities up to 1200 feet per second, can kill and have been used in accidental deaths, homicides and suicides; secondly, diabolo pellets may embolize just as bullets can; and lastly, minor external damage may mask major internal destruction.