As investigators continue to comb the Juab County desert for signs of missing West Valley City mother Susan Powell, experts are examining charred wood police found there and believe was used to burn human remains.
Last week, cadaver dogs alerted their handlers to the presence of human remains in an area where about 100 small pieces of wood were discovered buried near Topaz Mountain.
Lab work on the recovered wood would generally take three days but perhaps longer depending on a number of factors, said Tim Kupferschmid, executive director at South Salt Lake-City based Sorenson Forensics, who has more than 20 years of experience in forensic DNA testing.
"Some of the wood will be analyzed for volatile compounds to determine if accelerants were used to fuel this fire. Some of the wood may be swabbed for DNA to determine if significant amounts of biological material are present on the wood," said Kupferschmid, who is familiar with the process of DNA testing of materials such as those recovered by investigators last week.
It's possible to get a DNA profile from burned wood, Kupferschmid said, but the quality of the DNA depends on "the length of time in the fire, the heat of the fire and the amount of starting biological material present."
"If a fire was hot enough and burned long enough, biological material would not remain on the wood," he said.
Should the wood produce traces of DNA, scientists would work to establish a DNA profile.
When DNA is processed, the next step is to compare the DNA results with Powell's profile. The woman's DNA was likely collected by investigators from samples in her home, such as a toothbrush or hairbrush, Kupferschmid said. If police failed to do that, they could now collect DNA from Powell's children and do a "reverse maternity test," in which Powell's DNA would potentially be determined because it matched that of her children, he said.
If the DNA profile is not a match with Powell, scientists can work with law enforcement to see if there is a DNA match to other missing persons cases.
Sorenson Forensics contracts out its services to many law enforcement agencies, and the state forensics lab also can provide technology needed in cases where fragments are discovered in soil, he said. The dozens of cases Kupferschmid's business has assisted in include the 1998 slaying of 10-year-old Anna Palmer in Salt Lake City. After years of dead leads, advances in DNA technology allowed police to link scrapings from fingernail clippings from the girl's right hand to 32-year-old Matthew Breck, who lived down the street from Palmer in 1998.
Topaz Mountain is about 30 miles away from where Josh Powell, the only person of interest police have named in his wife's disappearance, says he took his two young sons camping the night his wife disappeared from their West Valley City home.
Police have said Josh Powell liked to gem hunt and family and friends have confirmed that Josh and Susan Powell had visited the Topaz Mountain area on previous family excursions.
West Valley City police recently conducted a search in the desert around Ely, Nev., and over the past months have conducted numerous searches in Tooele County. Police serving a search warrant also recently removed several computer towers and other evidence from the Washington home where Josh Powell now lives in with his father.
Susan Powell has been missing since Dec. 6, 2009. Josh Powell has said he had taken the couple's young sons, then ages 2 and 4, on a winter camping trip to Simpson Springs in Tooele County, and returned home to find his wife gone without a trace.
Juab County search continues Friday
Police and volunteers on Thursday spent an 11th day searching for any signs of Susan Cox Powell near Topaz Mountain in Juab County. West Valley City police Sgt. Mike Powell, no relation to the missing woman, said about 50 people searched near Topaz Mountain on all-terrain vehicles and on foot. The search will continue Friday.