Forensic DNA ethics_PhaseI

Police first used DNA forensically to establish identity. Tissue samples found at crime scenes are compared with DNA from known suspects or victims. A match can establish individual identity to a high degree of probability.

Then, DNAPrint -- a small genomic testing company in Florida -- offered a test that it used in more than 65 investigations. It translates DNA markers into a prediction of the "donor's" likely racial mix. The results, the company says, suggested that the [Baton Rouge serial] killer had 85 percent African ancestry and "moderately dark" skin. Detectives switched their search to the local black community and quickly focused on Derrick Todd Lee. They matched his DNA to that found at the crime scenes and have since won two convictions.

Such racial inferences from DNA go too far, [Stanford professor Mildred Cho] says. "We don't know whether the DNA can actually tell you anything about somebody's race or physical characteristics with that much certainty. Then, to obtain samples is an intrusion on their privacy, and I don't think it meets the criteria for probable cause," she says.

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