Lisa Bailey is a forensic artist (“the absolute coolest job in the world”) who wrote a book called Ask a Forensic Artist: The Art and Science of Law Enforcement's Most Unique Profession to show what is really involved in forensic work.
I know millions of people are interested in forensics, but there's little to no accurate information available about forensic art. I felt it was important to dispel some of the myths that are out there, and explain from start-to-finish what forensic artists do, and exactly how we do it. We need the public to help solve our cases, but they can't do that if they believe what they see on TV. Besides, the reality is a lot more interesting!
Neatorama is proud to present an excerpt from Ask a Forensic Artist, in which Bailey explains the process of facial approximation, or reconstructing a face from a skull.
Facial approximations (creating a likeness from an unidentified skull) are the coldest of all cold cases. By the time a skull gets to a forensic artist, all other means of identification have been exhausted. Years, maybe even decades, have passed. That’s why a facial approximation can literally be the last chance a person has to be identified. Which means it can also be the last chance for that person’s killer to be identified. Logically, an investigator can’t begin to figure out who the murderer is until the name of the victim is known.
Most people are fascinated by skulls, and I’d be lying if I said I were any different. But my curiosity isn’t morbid; I see every skull as a puzzle, and I’m in a constant search for answers. The more I know, the better I can do my job. I try not to stare in public when I see a particularly interesting-looking person, but I can’t help but look at the face and think, ‘what is going on under there? Why does she have that dimple in her chin? What causes her eyelids to fold that way? Why is one cheek higher than the other?’ The answers lie with the skull.
No two are alike. I used to think they were, until I got into this line of work. Not everyone has the opportunity to see even one skull in their lifetime, so there are no words for the first time I stood in a room with twenty skulls lined up in a row. All imaginable shapes, all imaginable sizes, and as different from each other as snowflakes.
And that right there is the key to facial approximation. The reason we each look like the individual we are is because of the shape and structure of our skull. Think of your skull as an armature, and the muscles, fat, and flesh as the fabric that is draped on top of it. If forensic artists can capture the basic facial structures and “look” of people based on their skulls, then we might just be able to help get them identified.
So, if you have wide-set eyes, it’s because your eye orbits are widely spaced on your skull. Square jaw? Square mandible. Wide nose? Wide nasal opening. Your skull also gives clues about whether your nose turns up or down. Unless you are in a public place and too embarrassed to follow along, feel under your nose. The hard part between your nostrils is a bony feature called the anterior nasal spine. This is what supports the fleshy cartilage of your nose, the part that is movable and wiggles. So, if your anterior nasal spine turns down, you will have a downward turned nose. If it points up, the tip of your nose will point up. Logically, a straight nasal spine would indicate a straight nose.
Nose direction follows the direction of the nasal spine
Of course, there are all different types of downward turned noses, just as there are all different shapes and sizes of upward turned noses. Because most of the nose is made of cartilage, there are some nuances we just aren’t going to be able to predict.
That’s why facial approximation is not an exact science. In fact, it’s not a science at all. Science deals with black and white, and with facial approximation there are still too many shades of grey to call it that. And that’s exactly why artists are involved in the process.
We have the skills and background in portrait art and facial anatomy; we know how to highlight certain elements of a person’s face, and play down others. Anthropologists have the scientific training and qualifications to give us guidance on features and any unique aspects of the skull they think should be emphasized.
Forensic artists would never presume to say that a facial approximation is going to be an exact likeness of an individual, and none of us should ever overstate our abilities or role in a forensic approximation case. It is always a team effort. Always.
I’m always asked if we have to clean the skulls we work on. Thankfully, we don’t, although I do know some artists with iron constitutions who have. Generally, skulls come to us through the medical examiner’s office, and if there is any residual tissue that needs to be removed from the skull, it will have been done there.
A common cleaning method is to soak the skull in warm soapy water until the tissue falls away from the bone. A crockpot is perfect for this; it keeps the water at a low, steady temperature without ever coming to a boil or damaging the remains.
That’s not to say the skulls are always pristine. I’ve worked on many with tissue still attached, and even with dried brain matter inside. As the skull is moved, remnants can fall out of the opening (foramen magnum) in the base of the skull. This is one good reason to wear gloves when handling a skull, besides the fact that we don’t want to contaminate it with our own DNA.
Clay is never applied to the actual skull, either. We can never forget that the skull isn’t just an irreplaceable piece of evidence; it is a person. Handling it any more than absolutely necessary, and especially applying clay directly on its surface, runs the distinct risk of damaging it. So, we always make a replica to work from, and the actual skull stays safely packed in the container it was shipped in, and only taken out for reference.
I usually begin the sculpture by positioning the eye in the orbit. It’s the one feature I agonize over the most, so it’s the one I start with so I can check it over, and over (and over) again. I want to make sure that each is positioned correctly and independently in each orbit. Faces aren’t symmetrical, so I can’t presume that the eyes will be even with each other; one may be higher or even more deeply set than the other.
Access to MRI data of living people, as well as studies from dissections on cadavers, has shown that eyes are not centered in the orbit. Instead, they sit about 1.5mm up and 2.5mm out from center. From the side, the eyes are set 16mm from the front of the cornea to the deepest edge of the orbital margin.
Eye position in the orbit
Placing and sculpting the eyes
Eyebrows generally follow the shape of the eye orbit, beginning just under the edge of the bone towards the center of the face, and arching slightly up toward the outside. Again, this is a generalization. We don’t have any data or hard science to guide us on how thick they should be, so we do our best to keep them fairly unobtrusive.
Determining eyebrow placement
The width of the nasal opening is about three-fifths the overall width of the nose. We measure the base of the opening with a pair of digital calipers and multiply that by 1.67. That gives us the approximate overall width at the ala, or wings, of the nose. In the example below, the aperture is 21 mm across, so the overall width would be 35 mm or, 7 mm added to each side.
Determining the width of the nose
We also get an indication of where the top of the wings of the nose should go. Inside the aperture is a bony feature called the interior nasal concha. The top part of the wing of the nose should correspond to the upper attachment point of the concha.
Determining the placement of the nasal wings
The guideline for sculpting the lips is to make them about the same as the height of the tooth enamel, but I can tell you right now that I haven’t seen much correlation between the two. You don’t need access to skulls to see that. Look at your friends and family: are their lips the same thickness as their teeth? Probably not. Instead, I take into account the age and ethnicity of the person being sculpted. For instance, I would generally make the lips of a fifty-ish white male on the thin side, and those of a twenty-year-old male a bit fuller.
I usually work on a skull feature by feature before fleshing out the rest of the face. Besides being a personal preference, it allows me to see how the thickness of the clay is relating to the bone underneath. After I have the features roughed in, I begin work on the cheeks.
Because we usually receive skeletal remains, with no hair available as a reference, I think it’s best to sculpt hair in a simple, unobtrusive style, appropriate for the age and sex of the individual. For men, this is usually a short generic haircut; for women, a soft hairstyle brushed away from the face.
Overall, there’s no way to quantify how many facial approximations will result in an identification. Some cases that are merely months old will never be solved, while others that are thirty years old will get a lightning-bolt stroke of luck and be identified within days of a news report.
Attempting to pin down numbers doesn’t change the fact that approximations can work. Period. Not always; there are no guarantees. But they work well enough and often enough, to know they are of value in helping to identify victims of crime.