In its four-decade existence, the DBE program has long wrestled with questions of how to determine if someone is a minority. Proof of race and ethnicity “has been a thorn in the side of the DBE program for years,” said a 2001 article in the magazine Government Contractor. But Taylor’s case appears to be the first time, according to Jennifer Sommerville, a lawyer who has written about DBEs, that DNA evidence has come up in a lawsuit over eligibility for the program.

According to several legal experts I spoke with, it might also be the first time a genetic ancestry test is being cited as evidence of race in any type of court case.

Currently, in situations like DBE certification, the legal system generally lets people identify their own race. Title VII employment-discrimination lawsuits are another common scenario where a person’s race is relevant. Richard Levy, an attorney who worked on a $98 million class-action lawsuit alleging racial bias in the New York City Fire Department, says the case relied on self-identification to decide who was eligible for the money. “If they identified as black, they were,” he says.

If DNA evidence somehow seems more tangible and less subjective than self-identification, consider the problems it would also pose.

For one, the accuracy of DNA tests are unproven—and the specific test Taylor took in 2010 is now widely seen as outdated. Today’s leading test companies, such as AncestryDNA and 23andMe, examine around 700,000 DNA markers, comparing them to a database of thousands of people around the world. Still, customers have found that different companies will return different results. And companies also frequently tweak their proprietary algorithms, so results can change from software update to update.

Big Pharma would like your DNA.

In contrast, the AncestryByDNA test Taylor took looked at just 176 DNA markers, according to government documents, less than one-thousandth of the current industry standard. Despite a similar name, the test has little to do with the more popular one from AncestryDNA. And in fact, a Google search of AncestryByDNA brings up dozens of angry reviews calling it a “waste of money” and warning customers about the confusing name. Taylor has offered before to take another DNA test at the government’s expense, but nothing has come of it.

Even if a perfectly accurate genetic ancestry test did exist, it would not easily settle questions of race. The percentage breakdowns of a test do not map neatly on to racial categories. How many African DNA markers does a person need to have to be considered black? Four percent? Twenty-five percent? Fifty percent? There are no universal cutoffs. Genetic variation is real, but the boundaries of racial categories are socially determined and have constantly shifted over the course of American history. “You cannot rely on DNA evidence alone to decide what is really a socially constructed concept,” says Sheryll Cashin, a law professor at Georgetown University.