The Federal Bureau of Investigation (FBI) might have just cracked its oldest case yet after using forensic DNA evidence on a 4,000-year-old human head.

The mystery began in 1915 when a team of archaeologists discovered a 4,000-year-old tomb in the Deir el-Bersha necropolis in Middle Egypt. However, the room looked more like a crime scene than a rich man's resting place. The ransacked tomb appeared to have been looted many centuries ago, leaving behind a decapitated, mutilated mummy thrown in the corner and a head perched on the coffin. The tomb belonged to governor Djehutynakht and his wife, but the question remained: who did the severed head belong to?

A new study published in the journal Genes appears to finally have the answer. The skull was missing many of its facial bones, meaning it was not possible to identify the sex of the remains using anatomical methods. So, they turned to DNA analysis techniques. While DNA can often serve as a pretty sturdy form of evidence, it’s extremely hard to obtain if the remains have been laying in a hot tomb for 4,000 years.

They got their hands on the DNA by drilling into the skull’s molar tooth and extracting 105 milligrams of tooth powder. Various teams of researchers had spent years trying to extract some DNA from the tooth, but to no avail, until the FBI was called in.

“At the time the FBI was contacted, the ancient DNA community had largely given up on the testing of ancient Egyptian human remains. Though DNA extraction and amplification from ancient Egyptian samples had been attempted in the early days of paleogenetics, these initial attempts either resulted in failure or yielded data that turned out to be the product of modern DNA contamination,” the researchers explained in the study.

The FBI used a technique to extract the genetic material, then mixed it with a liquid that amplifies the amount of DNA so it’s easier to study. Using this relatively new method, they determined that the biological sex of the head was male, strongly suggesting that this really is the skull of Governor Djehutynakht, not his wife.

Perhaps even more importantly, the research serves as another example that it’s possible to extract usable DNA from an ancient Egyptian mummy.

“I honestly didn’t expect it to work because at the time there was this belief that it was not possible to get DNA from ancient Egyptian remains,” Odile Loreille, a forensic scientist at the FBI, told The New York Times.

Just last year, at a similar time when this research was being concluded, scientists published the first genome analysis of ancient Egyptian mummies, revealing that they were more closely related to other ancient people from the Middle East, compared to modern Egyptians who are genetically closer to Sub-Saharan Africans.

The ancient Egyptians still hold on to many of their secrets, but increasingly advanced science is slowing shedding light into the tomb.

[H/T: The New York Times]