Putting pencil to paper has been the tried-and-true method to illustrate the faces of wanted criminals, but new technology is changing this traditional approach. DNA, rather than an artist’s skill, is an emerging tool to recreate the face behind a crime.

The new forensic technique is called DNA phenotyping. It relies on DNA, found for instance in a drop of blood, to create a simulated face based upon genetic markers. Although the science still has room to grow, start-up companies in the United States are already producing DNA-based sketches to assist police departments in criminal investigations.

Building the Face Generator

One of the leaders in this growing field of research is Penn State University’s Mark Shriver. In a study published in PLOS Genetics, Shriver’s team detailed the process.

First they compiled a list of known genetic mutations that cause facial and cranial deformations, because these genes, in their normal variations, could give us our distinctive looks. With these genes marked, researchers compared the genetic profiles of people with vastly different faces in order to highlight, through contrast, which genetic variations were at work. For example, the gene responsible for lip size would be expressed differently in someone with luscious lips than in someone with thin lips.
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An example of the 7,000-point face map used by Shriver’s team. (Shriver Claes/Penn State)

Next, researchers scanned those same faces to build a 3-D facial map with over 7,000 coordinates. By combining genetic and facial map data, researchers could link DNA markers with certain facial attributes to build a predictive algorithm. The technique can predict genetic ancestry, freckles, facial shape as well as eye, hair and skin color.

But it’s clear that DNA phenotyping is in its infancy. In their papers, Shriver’s team said their genetic analysis explained only 23 percent of variations in faces. Shriver and his team continue to refine their technique, and they’re homing in on other genetic variants that could help build more accurate faces.

Does it Work?