What Bones Can Tell Us About Crimes

Bones can tell us many stories. In life, they can tell us whether cancer or another disease is affecting our blood cells or marrow. In death, they can shed light on who we were, where we came from and sometimes how we died—including if we were the victim of murder. Bones often aid crime investigations and can help identify human remains, whether recent or historical.

In her new book Written in Bone: Hidden Stories of What We Leave Behind, renowned forensic anthropologist and human anatomist Sue Black explores the human skeleton and explains how each person's life journey is revealed in their bones. Black, who was lead anthropologist for the British Forensics Team's work in the war crimes investigations in Kosovo, and also worked in Thailand after the 2004 Indian Ocean tsunami, calls these "the last sentinels of our mortal life to bear witness to the way we lived it."

A&E spoke with Black about the information concealed within bones and how they can help solve crimes.

How do bones store a person's story and essentially give away secrets that others might not want known?

Bones are a long-term living and organic material. As you age, grow and go through life, certain events get written into your bones. It's like having your own internal USB [drive]. Bones reveal some of the things that you've gone through, give you an indication of how many years you've been on the planet, tell you about the ancestral groups your family came from, whether you have circulating levels of estrogen or testosterone…even when you fell off your bike when you were a teenager and broke a bone. Some conditions and diseases also manifest on bones.

There are some parts of your body that never regenerate. Some cells in your body are the same cells you were born with, and they never change. The skeleton takes about 15 years to completely regenerate itself. But, even so, if it's had a break, it never quite regenerates itself back to the way that it started. The skeleton is incredibly clever. With bones, your story is written into human tissue.

What other objects can masquerade as human bones and throw a crime investigation off?

The biggest one…is, of course, bones from other animals. You don't want to set off a murder investigation based on a chicken, because the chances of you getting a successful conviction will be really slim. If you look at chicken bones, they're incredibly similar to the tibia or shin bone of a newborn human baby. In a forensic case, we need to know as soon as possible if skeletal remains are human. Adults have 206 to 213 different bones. In a child, you'll have over 300 bones. We have to be able to identify every single bone in the human body, whether it's coming from a baby, child or adult. We also need to know whether it's an intact bone or if it's been fragmented.

Sometimes there are things that are not bone at all, but they look as if they could be. For example, we find questionable things at fires, because plastic melts and burns in a particular way that can leave odd shapes. At a fire scene, everything is black, so being able to determine whether you've got bits of bone or you've got bits of something else can be really challenging.

There was one case in the U.K. that involved a historic children's home where there was alleged to have been abuse. Whilst investigators were digging, they found this little sort of section that looked like a child's parietal bone, which is the one on the side of the head. It was actually a coconut shell.

In your book, you discuss a body that was recovered from a garden, a case that became known as ‘head in the shed.’ From the headless skeleton, you were able to confirm suspicions that the remains belonged to an elderly female. How did you make that determination?

In the first stages of identification, there are four characteristics that we look for: Are the remains male or female? What age was the individual when they died? What was their ancestral background? And what was their height?

With an investigation, you'll hear police say, 'he's a male, somewhere between 25 and 35, five-foot-six to five-foot-eight inches in height and white.' So, those four characteristics give us a template of the person we may be looking for or the remains we've found.

I'll point out that sex determination is not the same as gender. Gender is what we choose to present to our world, and we can change our gender. But the sex we're talking about, as forensic anthropologists, is, by and large, a genetic sex.

When you are in the early stages of puberty, your hormones are raging, and your body responds to those hormones. If you are female, those hormones will be estrogen. If you're male, they'll be testosterone. We've all got a bit of both. Testosterone is important in developing muscle. Sites of muscle attachment, in response to testosterone, become much bigger and the bones become much more robust. In the female, the pelvis changes shape as it's preparing for the possibility of childbirth. If we've got the pelvis, pretty much in 90 percent of our cases, we can tell whether the skeleton is from a male or a female. If we didn't have the pelvis, then we'd go and look at other areas. Are the bones shorter and or longer? Are they robust?

Also, as you go through different stages in your life, your body grows, matures and then deteriorates. Degenerative joint changes give us a clue as to whether remains are from a mature or elderly adult. In this particular case, we could confirm that she was likely to have been an elderly female. From looking at the skull, when we eventually got it, we were able to say that it looked as if she was Caucasian.

How do you determine if a skull belongs with a set of skeletal remains or if it belongs with another body?

In many parts of the skeleton, you can fit the bits together like a jigsaw [puzzle], but not always. What we'll often do is take DNA samples; one from the skull bone and one from another part of the skeleton. The hope is that they match up. We'll still do a quick and dirty fit, just to make sure, but DNA confirms a match.

Using skeletal remains, how do you determine a cause of death?

Pathologists determine a cause or manner of death, whereas anthropologists are about identification. We can be sort of a sparring partner for pathologists. When they've got ideas, they'll bounce them off us. In this [head in the shed] case, there was a fracture to the back of her skull. But that can't tell us whether something hit the skull, or the skull hit something. In other words, did she fall and that's what caused the fracture? Or was she hit by something, which is what then caused the fracture?

The pathologist would probably have put forth the cause as blunt force trauma, which likely resulted in internal hemorrhaging and would have labeled it, I suspect, as being suspicious.

When it comes to murder, which bone or bones in the human body tend to give us the most information?

With a traumatic death, you're looking at blunt force, sharp force or ballistic trauma. Most people who commit murder or manslaughter go for an area of the body that has a large surface area. You tend to find the trauma associated with the head, chest or abdomen, because those are large areas of the body where vital organs are housed.

Heads can also help us reconstruct a face. So, we like to have the trunk and head.

How far back historically can we go to solve crimes using a person's skeletal remains?

As long as we've got bone, we can go back as far as we like—thousands, if not millions, of years—even when bone is replaced by petrous material. When we have fossils, for example, you can still see some of the bone material. Bone survives incredibly well in the right environment, particularly in dry sandy soil, as opposed to wet, acidic soil.