Imperfect Justice_ Prosecuting Casey Anthony - Jeff Ashton [53]
INTRIGUING AS THE POSSIBILITIES WERE with the odor, they were only one part of the forensic evidence in our possession. My second forensic project was the hair collected from the trunk of the Pontiac. We wanted to establish that it was Caylee’s hair, but more specifically, we wanted to determine whether the hair had come from someone living or dead.
The person I called was Karen Lowe, a senior analyst in the Trace Analysis Unit of the FBI Crime Laboratory Division in Quantico, Virginia. Lowe was a scientist with eleven years’ experience at the lab. I read her report on the examination of the hair found in the trunk, and our conversation about her findings was professional and to the point, as you would expect. In her examination of the hairs, she discovered that one of them, a nine-inch light brown hair, had an unusual dark band at a particular point near the root. She explained to me that, while science has yet to understand precisely why this banding occurs, it has only been found in hairs taken from decomposing bodies. The banding was first documented in the scientific literature in the late 1980s and has been documented in numerous studies since. She noted that she had personally seen it hundreds of times in case work while examining hair known to have been taken from dead bodies, but that this was the first time she had seen it in a scene sample where the body had not been found. In the conservative fashion typical of FBI reports, she could only describe the banding as “apparent decomposition,” but with the explanations she was able to give me, I felt we had a bombshell.
The next issue was proving that it was Caylee’s hair. Lowe had examined the hair under a microscope and compared it with hair taken from a brush that the Anthonys said was Caylee’s. Hair comparisons aren’t like fingerprints; no expert can ever say with certainty that two hairs have come from the same person. By looking at the microscopic features of a hair, however, a scientist can eliminate some possibilities. Lowe explained that her comparison revealed that the hair with the banding was similar in length, color, and all other microscopic features to the hair taken from Caylee’s brush. She also compared it to samples of Casey’s, and she was able to say with confidence that the hair could not have been Casey’s, because her hair was colored with dye and too short. We knew that Cindy’s hair was dyed, usually blond, and kept short, and Lee’s hair was too short as well. In order to be as certain as possible, the hairs were passed on to the DNA section of the lab.
Now, because DNA can only be extracted from a living cell, ordinary DNA testing doesn’t work on a hair. Because the only living part of a hair is the root, decomposition makes the chances of successful regular DNA testing of hair slim to none. However, there is another kind of DNA test that can work on hair, a test that examines the DNA found in the hair’s mitochondria. The DNA in the mitochondria is much heartier than ordinary DNA, and therefore it exists even in the dead cells of hair. The downside of mitochondrial DNA (mtDNA) is that it is passed on only from mother to child; there is no contribution from the father. Your mtDNA is identical to that of all your brothers and sisters, your mother, all of her siblings, your grandmother, and all of her siblings. In other words, if there is an unbroken maternal connection, then the mtDNA is a match.
The results of the mitochondrial DNA tests were a match. This match, combined with the fact that we’d already microscopically eliminated Casey, Cindy, and Lee by length and color, made me pretty confident that the hair with the “death band,” as the media would come to call it, was Caylee’s. With Dr. Vass’s findings and the other evidence of the smell, it seemed a sad but inescapable conclusion that Caylee was dead.
Still, the challenges to all these forensics would be many. The Frye hearings would be a monster. No doubt the defense would be digging up opposing experts, who were often attracted to big cases for the notoriety it would