Thursday, July 7, 2011
In the wake of the Casey Anthony verdict, I thought that I would do another post about cadaver dogs. In my prior post on the subject, I compared the standards used by courts (or at least the Court of Appeals of Texas) in allowing testimony concerning scent-lineup dogs and cadaver dogs. As I noted in that post, the Court of Appeals of Texas has held that
In determining whether a dog used in a scent lineup was qualified, we have applied five factors....In Risher, we held that a scent-lineup dog is qualified if "it (1) is of a breed characterized by acuteness of scent and power of discrimination, (2) has been trained to discriminate between human beings by their scent, (3) has been found by experience to be reliable, (4) was given a scent known to be that of the alleged participant of the crime, and (5) was given the scent within the period of its efficiency."... The Fourteenth Court of Appeals applied these same five factors in Winston to determine the reliability of a dog that tracked a burglary suspect based on human scent left at the crime scene.
Conversely, the Court of Appeals of Texas held that
Searches by cadaver dogs are different from searches by dogs for scents left by live humans. Deputy Pikett testified that cadaver searching is a less rigorous skill because it only requires the dog to be able to distinguish between human scents and animal scents, and the dog need not further distinguish between individual humans. As we explain below, because the skills necessary for a cadaver dog differs from the skills necessary for scent lineups or the tracking of suspects, we conclude that only some of the five factors in Risher apply to searches by cadaver dogs.
The rest of the post then went into more detail about the ways in which it is easier to admit cadaver dog testimony that scent-lineup dog testimony. But should cadaver dog testimony be readily admitted? Is the use of cadaver dogs generally accepted in the relevant scientific community, the only factor under Frye and one of the factors under Daubert? That was the question addressed by the Court of Special Appeals of Maryland in Clark v. State, 781 A.2d 913 (Md.App. 2001).
In Clark, Hadden Clark was convicted of the murder of Michelle Dorr despite the fact that Dorr's body had not then been located. What the police did find was a map of a cemetery with an asterisk during a search of Clark's truck, and they used the map to find the place where Clark allegedly temporarily buried Dorr's body. Police then "released the hounds." A first cadaver dog, Dan, criss-crossed the cemetery, then indicated an alert in the area of a soil disturbance, which was near a headstone marked "Clark." A second cadaver dog then alerted on an area behind Haden's grandfather's grave, which was the same place where Dan had initially alerted.
Hadden later filed a motion in limine to exclude cadaver dog testimony, and
At the hearing concerning the motion in limine, [Hadden] presented the testimony of Dr. Ann Marie Mires, the Director of the Identification Unit of the Boston Medical Examiner's Office, who qualified as an expert in the field of forensic anthropology and the identification of human remains. Dr. Mires has experience using dogs to locate human remains in cemeteries. In light of modern embalming and burial practices, she believed a properly trained cadaver dog would be able to distinguish a legitimate grave from a clandestine one within a cemetery because during embalming all body fluids are drained from the corpse, whereas persons who bury corpses in clandestine graves usually do not remove body fluids.
According to Dr. Mires, there are only three tools available to locate clandestine burials of human bodies: Trained cadaver dogs, ground penetrating radar, and shovels. In Dr. Mires's opinion, the alert of a cadaver dog, standing alone, is not considered sufficient to show to a reasonable degree of scientific certainty that human remains are or were present at the location of the alert. After a cadaver dog alerts, digging or ground penetrating radar are used. But the fact that neither of these instruments reveals a body does not necessarily invalidate the cadaver dog's alert, because there is no chemical test yet devised that can confirm whether a body had once decomposed at a particular site. Dr. Mires is participating in the preliminary stages of scientific work to develop such a chemical test.
Dr. Mires testified that the use of cadaver dogs "in trying to determine the existence or the one-time existence of human remains at a particular location is a concept that is widely accepted in the forensic anthropology and pathology fields." Despite this reliance, a dog can falsely alert because water flowing from the site of a human cadaver may cause the dogs to alert at a place removed from the spot where a body was buried or because the dog is fatigued or because the handler misreads a dog's actions.
The trial court, however, denied the motion in limine. After Hadden was convicted, he appealed, claiming, inter alia, "that the evidence regarding the alerts by the cadaver dogs was inadmissible because 'it was unreliable' under Frye/Reed and Maryland Rule 5-702." Specifically, Hadden argued that
The process of training dogs to alert on the products of decomposition, as opposed to training them to alert on cadavers themselves, is not generally accepted within the scientific community, and accordingly, it does not meet the standard set forth in Md. Rule 5-702 or in the Frye/Reed cases. As argued supra, Dr. Mires admitted that research into this training and use of dogs is in the preliminary stages, and is not yet fully accepted. It is not sufficient to show, to a reasonable degree of scientific certainty, that human remains are or have been present. Since this technique for finding and identifying soil in which human remains were once present is not generally accepted by the scientific community, the judge erred in admitting evidence relating to it.
The Court of Special Appeals of Maryland disagreed concluding that this argument was
based on a false premise, i.e., that Dr. Mires "admitted that research into [the]...training and use of dogs is in the preliminary stages, and is not yet fully accepted." Dr. Mires never testified that research that delves into the training and use of cadaver dogs is in the preliminary stages. What was, according to her testimony, in the "preliminary stages" was her own work in attempting to discover a way of detecting fat, muscle, liquid, and other human byproducts that are deposited in the soil when a human body is decomposing. And, as already mentioned, Dr. Mires said that the use of cadaver dogs in trying to determine the existence, or the one-time existence, of human remains at a particular location is a widely accepted practice in the fields of forensic anthropology and pathology. Under these circumstances, the Frye/Reed test was met.