No one knows for sure when the world's first homicide took place - - other than Cain and Abel, that is. But it just might have happened 43,000 years ago in northern Spain. A skull retrieved from the Sima de los Huesos (Pit of Bones) in the Atapuerca Mountains showed two circular puncture wounds in the forehead of the skull. The skull had been found shattered into 52 fragments but miraculously was nearly complete. Once it had been reassembled the two wounds were easily identified. Researchers believe they were made by the same instrument and that they were not consistent with a simple fall into the cave shaft.
When you examine the skull it definitely looks as though some pointed instrument, most likely a stone tool or weapon, had delivered the blows. Of course, the assailant could claim self-defense, but this looks like a homicide.