WHYY Interviews Skip Palenik on the Role of Hair Evidence
WHYY, Philadelphia’s National Public Radio affiliate, recently broadcast an interview with Microtrace founder Skip Palenik on the role of hair evidence in forensic investigations.
Last Friday, “The Pulse,” a weekly segment that features stories relating to science and innovation, featured the story of Kirk Odom, who served more than two decades in prison on a rape conviction. The key evidence in the case was a hair sample from the perpetrator, which was incorrectly linked with Odom due to faulty testimony by a hair examiner. Years after his release, Odom was exonerated by DNA evidence.
In the interview, Skip spoke on both the usefulness of forensic hair analysis, and also its limitations.
To read the full article and listen to the interview, please click here (interview with Skip begins at 3:39).
A case of ‘overconfidence’
For Skip Palenik, who analyzes hair and other fibers under the microscope for a living, he says a lot can be gleaned from hair, such as whether its from an animal, and its types of pigments and colors.
“You can certainly tell a lot from hairs,” he said.
He often uses the structure of a pencil as an analogy for describing the microscopic anatomy of a hair, with its different cellular coatings and layers.
But part of the problem, he says, of the FBI hair testimony, is that as much as he loves the science of hair and what it can reveal under the microscope, “trying to say if two hairs came from an individual, you can’t do that so well. And the reason you can’t is there are only a limited number of characteristics that hairs have in first place.”
In other words, hair is just not as unique as one might hope.
Palenik says these days, comparative analysis can help narrow down which hairs are the best candidates for mitochondrial DNA testing, but he thinks that “at some point along the way, some people at the FBI and in other public sector labs developed what I think of as overconfidence in what can you tell from hairs.”
WHYY is Greater Philadelphia’s largest public media provider, serving southeastern Pennsylvania, southern New Jersey and all of Delaware for more than 50 years on television, radio and the Web.
The Pulse airs weekly on Fridays at 9:00 am and is rebroadcast on Sundays at noon.