Supreme Court Rejects DNA Challenge

It’s looking bad for Troy Brown. In 1994, Troy was convicted of raping a 9 year-old girl referred to as Jane Doe (a pseudonym to protect the underage victim's privacy). At the time, the most damning evidence against Troy was that DNA recovered from the victim's rape kit was consistent with his DNA profile. The laboratory correctly calculated that the chances that an unrelated individual would share this same DNA profile (known as the random-match probability) was 1 in 3,000,000.

Pretty damning indeed. Yet the prosecution misrepresented the significance of this evidence to the jury in two critical ways. To begin with, the prosecutor conflated the random-match probability with the probability that Brown was innocent, literally stating that there was only a .000033% chance that Troy was innocent -– a classic statistical maneuver known as the prosecutor's fallacy. Second, the prosecutor said the probability that one of Troy's brother's would share the DNA profile recovered from the rape kit as 1 in 6500, instead of the more accurate 1 in 66. That’s a critical point, because Troy's brothers, Trent and Travis, both lived in the same trailer park as Troy, and Jane Doe had even identified Trent as her attacker at one point.

Now, in its first opinion of 2010, the United States Supreme Court has denied Troy a new trial, despite faulty DNA evidence. The Court agreed that the prosecution had done a bad job representing DNA statistics, but said that Troy raised his valid objection under the wrong legal standard. It’s privileging form over substance, but while that may seem unjust, the result isn’t as bad as it sounds. In its ruling, the Court left open the possibility that Troy’s lawyer had failed to call out the prosecution's DNA errors. It’s still possible (though not likely) that Brown could get relief on this point.

And in the end, the Court's decision is actually reasonable. Brown's innocence claim may not have been all that strong, and he hasn’t actively sought to implicate his brothers in the crime (for example, through further testing to see if Trent's DNA actually matches the rape-kit DNA). But allowing him to pursue a claim against his lawyers is fair. The case was also a great opportunity for the Supreme Court to shed some light on –- and condemn -- the prosecutor's fallacy, which I hope can help curb the tendency of prosecutors to overstate shaky DNA evidence. Given the Roberts' Court conservatism, the decision isn't nearly as bad as it could have been.

Photo Credit: Txspiked