In a remote part of Northern Spain, at an archaeological site known as Sima de los Huesos (literal translation - Pit of Bones), a team of researchers have found what could possibly be the first recorded case of a murder being deliberately committed. The site in question is actually an underground cave system, with the only access being through a narrow 13 metre vertical shaft.
     Several skeletal remains have been found in the caves (totalling at least 28 individuals so far), at the bottom of the shaft, dating from approximately 430,000 years ago, in the Middle Pleistocene Era. The team have managed to piece together one skull, from 52 fragments. Complete that is except for two identical holes, which it is believed, were caused by two blows on the upper forehead from an unknown source.
     This conjecture has been confirmed by using modern forensic techniques, which prove beyond doubt that the blows/impact was sufferer before either an accidental or deliberate fall down the shaft (too identical to be caused  by impact during the fall). Accidental? It is thought not, the current theory being that the cave was actually part of some funerary or sacrificial site.
     One member of the team, Rolf Quam, a paleoanthropologist from Binghampton University (USA) is quoted as saying "One implication of the study is that murder is a very ancient human behaviour". Danielle Kurin, from the University of Santa Barbara USA (who is a forensic anthropologist, but was not part of the research team), added "Keeping in mind these guys were robust and this was one of the denser parts of the skull, you would need a lot of force to make a fracture that causes the bone to get knocked into the brain." Rolf Quam added: "We are pretty sure that these two fractures are the result of two repeated blows with the same implement, and that implies a clear intent to kill".

Edited from PhysOrg, Mirror (27 May 2015), Stuff.co.nz, The Scotsman (28 May 2015)