"Two episodes of "localized blunt force trauma" to the skull with 'an intention to kill.' 3-D imaging to re-create the injuries. Bodies dropped down a 43-foot-deep vertical shaft into a mass grave. A murder case — more than 435,000 years old."

"It's all detailed in a study in the journal PLOS One called 'Lethal Interpersonal Violence in the Middle Pleistocene,' and its authors say it's evidence of one of the earliest murders on record."

"One of the authors of the study, Rolf Quam of Binghamton University, spoke with NPR and said the evidence they found, which includes a skull reconstructed from about 50 fragments, clearly points toward murder. Two major injuries on that skull, above the left eye, couldn't have both happened unintentionally."