The skull of a prehistoric human relative was found in a cave in northern Spain. Scientists said the 430,000-year-old skull showed signs of homicide: two fractures inflicted by the same weapon. (JAVIER TRUEBA/MADRID SCIENTIFIC FILMS VIA REUTERS)

It’s a classic murder mystery: no motive, no weapon, no suspect. Just a body, dumped in a remote location with fatal head injuries. It would be standard fare for an episode of “CSI” — except it happened 430,000 years ago. That makes it the earliest documented case of homicide, researchers reported last week in PLOS One.

The victim spent almost half a million years entombed in a cavern called Sima de los Huesos, or “Pit of Bones,” in northern Spain. Since the cave’s discovery in the 1970s, researchers have unearthed nearly 7,000 bone fragments from at least 28 individuals of the Homo genus. And now they’ve uncovered the first evidence of foul play.

A skull known as Cranium 17 belonged to an otherwise healthy young adult who died from wounds that left two gaping forehead holes, says Nohemi Sala, a paleontologist in Madrid. Sala’s team pieced together 52 bone fragments from Cranium 17 to create a 3-D model of the skull. Then the team analyzed the fractures above the left eye to determine whether someone had had it in for the victim.

The two holes are nearly identical in shape and size, suggesting multiple blows from the same weapon and a clear intention to kill. By calculating the trajectories, the researchers determined that the blows flew from different directions. It’s hard to imagine that happening by accident, says Jörg Orschiedt, an archaeologist at the Free University of Berlin who was not involved in the study.

Although ancient members of the human evolutionary family suffered plenty of injuries — usually from mishaps or predators — prehistoric homicide appears to have been rare, says Haagen Klaus, an anthropologist at George Mason University. The discovery marks just the third potential murder case of the Pleistocene epoch, which ran from 2.6 million to 11,700 years ago. “If such violence was more frequent, then we would expect to see more evidence of it,” Klaus says.

However, Sala says it’s challenging to find definitive proof of murder in the archaeological record. “We are not saying that this is the first time that it happened,” she says. “This is the first time we can actually be sure.”

— Science News