Opinion ID: 2036519
Heading Depth: 1
Heading Rank: 20

Heading: Dog Hair

Text: Kenneth Knight testified that animals generally have three types of hair: fur, which insulates the animal; guard hairs, which protect the animal; and tactile hairs, such as whiskers. Guard hairs are used for comparison because they have the largest number of characteristics to compare. Knight recovered 32 guard hairs from the victim's clothing: 14 from the socks, 4 from the shoes, 4 from the underpants, 4 from the shorts, and 6 from the shirt. In addition, he obtained a single guard hair from Richard Caudell, which Knight was informed had been removed from the victim's underpants. Knight compared these hairs with hair standards from defendant's dog, Babe, a black Labrador retriever, and concluded that the hairs found on the clothing were consistent with Babe's hair and could have originated from Babe. Knight also compared the dog hairs from the victim's clothing with hair standards from nine dogs in the victim's environment, including five dogs owned by the Schulz family. The hairs found on the victim's clothing were dissimilar to these hair standards. In addition, Knight examined one dog hair recovered from the transport sheet. This hair was also consistent with Babe's hair and dissimilar to the hair standards from the victim's environment. Knight testified that during the processing of defendant's vehicle he observed animal hair throughout the vehicle and that all of the tapings from defendant's vehicle contained dog hair. Knight sampled 90 hairs from the front right passenger carpeting, which he concluded were consistent with Babe and could have originated from Babe. Several of the dog hairs found on the victim's clothing, as well as standards from defendant's dog, were provided to Joy Halverson of QuestGen Forensics for mtDNA testing. Halverson testified that the same mtDNA process used on human hair is used on animal hair, but the number of base pairs compared is 655. Like human mtDNA, dog mtDNA does not distinguish among maternal relatives. Halverson tested eight animal hairs from the victim's clothing and standards from Babe and concluded that the eight hairs were a match with Babe. In order to determine the significance of the match, Halverson compared the mtDNA sequence found in this case with the 345 sequences contained in a dog DNA database she developed. The sequence in this case appeared nine times in her database, indicating a frequency of 2.6%. She explained that dog mtDNA is less discriminating than human mtDNA and that a match in this case means that if the dog population in general were sampled, one out of 38 times the same mtDNA sequence would be seen. Halverson also testified that evidence suggests no correlation between a dog's breed and its mtDNA sequence. Thus, a German shepherd and a Dachshund could have the same mtDNA and two German shepherds could have different mtDNA. Christopher Basten, an expert in statistical analysis of DNA results, reviewed Halverson's report. He testified that the database Halverson used was valid and a reasonable approximation of dogs throughout the United States. According to Basten, an alternative way of expressing the results Halverson obtained is to say that it is 38 times more likely if Babe or a litter mate is the source than if it's some unrelated dog. Basten applied a confidence interval to Halverson's results and obtained a likelihood ratio of 21, which says that it's at least 21 times more likely if Babe or a litter mate is the source than if it's some random dog. And you could also say it's one in 21. Robert Makuch, a defense expert on biostatistics, challenged the validity of Halverson's database, testifying that 345 sequences is a small number to be representative of the entire dog population of the United States. He also testified that the method of obtaining the sequences must guard against bias and that a random sampling of dogs from each of the 50 states could produce a database different from the one Halverson compiled.