Using only DNA left at a crime scene as a reference, some law enforcement agencies are developing and releasing sketches of what the perpetrator might have looked like, the New York Times reports. In South Carolina, police released such an image from a stalled murder investigation. It, the Times notes, generated a couple of leads, though they didn't work out.
Such an approach, called forensic DNA phenotyping, examines markers in samples left at a crime scene to determine the suspect's eye and hair color, and may soon also be able to figure out his or her skin color, hair curliness, tooth shape, age, and more.
"That at least narrows down the suspects," Susan Walsh from Indiana University-Purdue University Indianapolis, who was awarded a Department of Justice grant to develop such tools, tells the Times.
Others, the Times notes, say the technology isn't quite there yet, especially for faces. "While inheritance clearly plays a big role — identical twins look alike, obviously, and people resemble their close relatives — some experts say not enough is known yet about the relationship between genes and facial features," it says.
In its own sort of experiment, the Times had images made of some staff members based on their genotypes and circulated them around the newsroom to see whether anyone could identify their colleagues, as it recounts in a related piece. No one was able to identify John Markoff, while 10 people could pick out Catherine Spangler based on their DNA-generated images.