Prosecutors are reviewing more than 250 serious and violent felony cases in which DNA played a crucial role in convicting the defendant because the investigations involved a now-discredited DNA interpretation method.
The DA’s office has sent letters to attorneys for those defendants, inviting them to discuss the cases, some of which may be reopened or retried.
Attorney Matthew Speredelozzi, whose research on behalf of a convicted killer helped prompt the review, said the questionable convictions involve what lawyers call “mixed DNA” evidence. That evidence consists of DNA from more than one person that is found on a weapon or other object connected with the crime.
Speredelozzi and other defense attorneys said a protocol used by crime labs from 2003 until as recently as 2016 overstated the probability that the DNA in question came from the defendant.
"DNA has this reputation for being, you know, black-and-white,” Speredelozzi said, in reference to mixed DNA cases. “But it's not black and white. In fact, in many instances, it's highly subjective.”
The district attorney’s office reviewed 1500 cases where mixed DNA played a crucial role in the defendant’s conviction.
Deputy District Attorney Brent Neck said 250 of those convictions deserve a closer look.
In a January 22 letter to defense attorneys associated with those cases, the DA’s office said “...it is likely that only a very small number of cases will be affected” by the review, but promised to “… work cooperatively with (defense) counsel to find an appropriate remedy in any case in which our confidence in the conviction is undermined.”
Speredelozzi said the DA’s office should have moved faster with the review, but prosecutor Neck said his office is committed to revisiting any questionable conviction.
"Just because a person is convicted, it doesn't mean that case is forever closed,” Neck said. “If there's later, new evidence or new technology that would suggest that a person is innocent, we're going to act on it, and we're going to act on it quickly."
Defense attorneys say there could be tens-of-thousands of these “mixed DNA” convictions needing review nation-wide.