There were no known eyewitnesses to the murder of a young woman and her 3-year-old daughter four years ago. No security cameras caught a figure coming or going.
Nonetheless, the police in Columbia, S.C., last month released a sketch of a possible suspect. Rather than an artist’s rendering based on witness descriptions, the face was generated by a computer relying solely on DNA found at the scene of the crime.
It may be the first time a suspect’s face has been put before the public in this way, but it will not be the last. Investigators are increasingly able to determine the physical characteristics of crime suspects from the DNA they leave behind, providing what could become a powerful new tool for law enforcement.
Already genetic sleuths can determine a suspect’s eye and hair color fairly accurately. It is also possible, or might soon be, to predict skin color, freckling, baldness, hair curliness, tooth shape and age.
Computers may eventually be able to match faces generated from DNA to those in a database of mug shots. Even if it does not immediately find the culprit, the genetic witness, so to speak, can be useful, researchers say.
“That at least narrows down the suspects,” said Susan Walsh, an assistant professor of biology at Indiana University-Purdue University Indianapolis who recently won a $1.1 million grant from the Department of Justice to develop such tools.
But forensic DNA phenotyping, as it is called, is also raising concerns. Some scientists question the accuracy of the technology, especially its ability to recreate facial images. Others say use of these techniques could exacerbate racial profiling among law enforcement agencies and infringe on privacy.
“This is another of these areas where the technology is ahead of the popular debate and discussion,” said Erin Murphy, a professor of law at New York University.
DNA, of course, has been used for more than two decades to hunt for suspects or to convict or exonerate people. But until now, that meant matching a suspect’s DNA to that found at the crime scene, or trying to find a match in a government database.
DNA phenotyping is different: an attempt to determine physical traits from genetic material left at the scene when no match is found in the conventional way. Though the science is still evolving, small companies like Parabon NanoLabs, which made the image in the South Carolina case, and Identitas have begun offering DNA phenotyping services to law enforcement agencies.
The Toronto Police Service has submitted DNA from 29 cases dating from the early 1980s through 2014 to Identitas. In 10 instances, the quality of the sample was too poor for any analysis to be done.
In a number of other cases, “it’s enabled us to actually change the direction we were focused on originally,” said Detective Sergeant Stacy Gallant, a cold-case homicide investigator. But there have been no arrests or convictions as a result, he said.
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Article courtesy of The New York Times, By ANDREW POLLACK, 2/23/15