From Tallahassee I’d flown—through Atlanta, of course—to D.C.’s National Airport. I’d spent a pleasant, productive lunchtime with Ed Ulrich, a former student of mine, who was now a physical anthropologist at the Smithsonian Institution. Borrowing from the Smithsonian’s vast collection of skulls, Ed had found a mandible that articulated nicely with the cranial vault of the black Florida teenager. Once we’d cobbled the pieces together, one of the Smithsonian’s radiology technicians had run the skull through the museum’s CT scanner. After that, Ed had steered me here, to the high-tech office of Joe Mullins.
Mullins, like Joanna Hughes, was skilled at re-creating human faces on bare skulls, guided by the architecture of the bone itself and by my insights about the boy’s age, race, and sex. Over the years, the National Center for Missing and Exploited Children—whose initials, NCMEC, were pronounced “NICK-meck”—had gained renown for its “age progressions” of missing children’s photos. Starting with the last or best photos of a missing child, NCMEC’s age-progression artists created images showing how that child might look two years later, and four years later, and so on, up to early adulthood. Their results spoke for themselves: their age-progression photos had made it possible for people to recognize and identify hundreds of missing children, sometimes many years after they’d disappeared.
But facial reconstruction was a newer and smaller niche at NCMEC, and Mullins was the only artist on staff who filled it. His method was a fascinating combination of old-school artistry and gee-whiz technology. He had a degree in fine art, but his workstation was straight out of Star Trek. To the right of his monitor stood a gizmo that looked like a small robotic arm—an arm with two elbows instead of just one, and a penlike stylus on the end where a hand ought to go. My assistant, Miranda, frequently used a similar-looking device, a 3-D digitizing probe, in the UT bone lab. Miranda used it to take measurements of skulls: all she had to do was touch the tip of the probe to prominent points, or landmarks, on the skull—the bridge of the nose, the tip of the chin, the cheekbones, the brow ridge, the crown of the head, and so on—and the digitizing probe would capture the spatial coordinates. Once she’d touched all the landmarks, the skull’s key dimensions would be recorded in our forensic data bank, which contained measurements from thousands of other skeletons. If the skull was an unknown—a John or Jane Doe, rather than a Body Farm donor whose identity was already known to us—our ForDisc software could then tell us the likely race and the sex of the unknown skull by comparing it to measurements from known skulls. ForDisc gave us a computerized way of doing, in a matter of minutes, what it had taken me decades to learn to do. I still made my own judgments, and I tended to make them faster than Miranda could digitize the measurements and run the software. ForDisc was a useful backup, though . . . and once, when the software and I had disagreed about the race of an unknown skull (I’d said “white” and ForDisc had said “black”), I’d been wrong and ForDisc had been right.
But NCMEC’s digital arm had a very different use than ours did. As I watched, Mullins gripped the stylus and used it to move the computer’s cursor—a tiny icon shaped like the stylus—to a drop-down menu on one side of the screen. There, he latched onto a small cylindrical shape representing a tissue-depth marker and dragged it over to the CT image of the skull, then stuck it onto the bridge of the nose. He swiftly repeated the process with more markers, which he attached to other landmarks along the midline of the skull: the top of the head, the center of the forehead, the brow ridge, the end of the nasal bone, the tip of the chin, and the indentation between the base of the nose and the top teeth. He moved the stylus swiftly and fluidly, with no wasted movements, but I found myself wondering how he knew exactly when to click the button that seemed to transfer the markers from the stylus to the skull. “Do you just hover over the right spot? How do you let go of the marker and get it to stick to the skull?”
“I’m just pressing it on,” he said. “I feel it when I bump up against the bone.” He saw me puzzling to take this in. “Here, try it.” He rolled his chair to the side and allowed me to take his place at the computer and grip the stylus. I moved it tentatively back and forth, up and down, in and out, and then in a series of spirals. It moved freely, almost weightlessly, in all directions, with virtually no friction, as the tiny icon flitted and spiraled across the computer screen, floating around and above the image of the skull.
“That’s cool,” I said, “but I still don’t quite get how you transfer the depth markers onto the skull.”
“Move it in closer, all the way onto the skull.”