Lt. Roy Paschal, a forensic artist with SLED, show the CSI: Columbia class the characteristics of a male jaw bone using a plastic cast of a real skull.

Due to great interest in crime show dramas like CSI: Crime Scene Investigation , the Shepherd's Center of Columbia held a nine-week class called CSI: Columbia. The class featured a different speaker each week who specializes in a particular field of criminal investigation. This was the last class in the series.

He couldn't tell you the color of her hair. He couldn't tell you the color of his eyes. But he can show you what their faces looked like, using only their skulls.

Lt. Roy Paschal is a forensic artist. He has worked with SLED for nearly 30 years, creating 2-D and 3-D facial reconstructions from unidentified human skulls. These sketches and sculptures help law enforcement and the public identify to whom found human remains belonged.

Paschal was the speaker March 15, 2006, at the CSI: Columbia class. He structured the class as a tutorial, giving the basic steps in 2-D facial reconstruction.

One of the first steps in reconstructing someone's face, Paschal said, is to look at the skull to determine race and sex. This step is completed at SLED by Dr. Ted Rathbun, a forensic anthropologist.

There are certain markers in a skull that help identify a person's race, Paschal said. For instance, Asians have wider cheekbones than other races, Caucasians have longer faces, and Native Americans have teeth that are curved on the back.

The next step, Paschal said, is to determine build, which can only be done through other items found with the remains.

"You tend to see consistency throughout the body," Paschal said, so if you find a small size ring or belt with the remains, you can say the person had a thin frame. This would mean the person's face would most likely be thin as well.

Next, measurements are taken of the skull and various mathematical formulas are applied. The resulting calculations give estimates of tissue depth in different areas of the face.

The next step is to determine the look of the eyes. The average adult human eye is 24 millimeters in diameter, which is only 10 percent larger than the diameter of the average infant's eye. The adult human iris is around 10-11 millimeters in diameter.

The variation of human eyes comes in their placement within the skull. One way to determine placement is to place the center of the eyeball at the intersection of the widest points of the eye socket; the other is to use the tear duct and outer corner of the eye to determine placement. Paschal said he usually uses both methods as a double check.

Nose length and width are determined based on averages for the race and sex of the person. The direction of the nose (whether it points up, down, or straight) is determined by the direction of the nasal spine. The nasal spine is the bone at the bottom of the nose.

Other formulas are then used to determine approximate lip length, ear location, and ear size.

"It's not a perfect system, but it can get us close," Paschal said.

Paschal showed the class several side-by-side examples of sketches he completed from skeletal remains and the person's photograph once identified. The resemblances were incredibly close.