Category: Criminal Law

By Dov Fox

New technologies can put pressure on the logic of the law. Consider the well-settled legal conclusion that equal protection rights don’t apply when police use race-based descriptions to look for suspects. An emerging forensic technique called DNA phenotyping makes it hard to defend this reliance on racial proxies–rather than appearance itself–in the investigation of crime.

Phenotyping promises to use a piece of hair or skin left at a crime scene to infer an unknown person’s physical characteristics like eye color, nose shape, and cheekbone width. A groundbreaking new study — featured in last week’s Nature, New Scientist, and Time Magazine — used high-resolution 3D images and facial recognition software to approximate the facial features of almost 600 people of mixed ancestry from their DNA.

I consider the scientific, constitutional, and criminological implications of this technology in The Second Generation of Racial Profiling. I argue that reliable DNA phenotyping would force us to rethink whether race-based suspect descriptions are the kind of racially classifying state action subject to strict scrutiny–and it would lean on the narrow tailoring requirement that the state use race-neutral alternatives when possible. I summarized my replies to the best policy objections in a short piece on The Future of Genetic Privacy:

Critics of the forensic technique argue that its adoption would imperil individual privacy and facilitate racial profiling. These objections are important, but they’re overstated. What “a person knowingly exposes to the public,” the Supreme Court has held, “is not a subject of Fourth Amendment protection” against unreasonable searches and seizures. And statutory safeguards could be afforded for sensitive external traits about whether a suspect has changed genders, for example, or had plastic surgery.

Racial profiling is another concern. That the technology could be used to target minorities at disproportionate rates, however, gives no reason to think that such misuse is probable or any more likely than DNA dragnets or stop-and-question sweeps based on race-based suspect descriptions. The adoption of more precise physical markers in place of notoriously unreliable eyewitness observation would improve arrest accuracy and enhance police legitimacy.

The more serious worry is that DNA phenotyping might resurrect discredited conceptions of racial biology. If the [National Institute of Justice-funded] technology works as well as the government is banking it will, however, then replacing race-based suspect designations with the colors and shapes of facial features could, to the contrary, loosen the hold that race has on the way that people think about crime. Today’s all-points-bulletin for a “black man” could give way to tomorrow’s search for a suspect with dimples, copper complexion, and green eyes.

Wouldn’t police just filter these markers into racial terms? Maybe not, if they’re trained like clerks at a makeup counter are to trade in racial identifiers for face shapes and color tones. Besides, measures short of prohibition would likely soften whatever risk the adoption of DNA phenotyping would pose to egalitarian norms — for example, requiring higher burdens for investigatory use, or racial impact assessments of the kind that gained national prominence after the Supreme Court struck down a key provision of the Voting Rights Act.