New DNA odds spur review of old cases

DNA HelixTexas criminal justice organizations have begun reviewing thousands of cases that relied on an outdated method for calculating the odds that a particular person left DNA evidence at a crime scene.
At issue are samples that include more than one person’s DNA, such as evidence swabbed from a countertop after a convenience store heist or taken from bodily fluids in a rape kit. Experts revised national guidelines for calculating odds in these scenarios six years ago, but no one sounded an alarm or asked prosecutors to re-examine cases that used the previous methodology.