Charred wood recovered in Susan Powell search could produce clues, expert says

DELTA — It's the only evidence that has been recovered during a lengthy search around Topaz Mountain.

About 100 charred pieces of wood was taken from what was initially described as a shallow grave that had been disturbed. The material was discovered as investigators were searching the desert area for clues in the disappearance of missing West Valley mother Susan Cox Powell.

But is the material really evidence? And what can be gleaned from them?

A South Salt Lake-based forensics expert says plenty.

"If the wood is only partially burned, for instance — or didn't burn that long or wasn't that hot — and it was in direct contact with biological materials, then it is possible to get a DNA profile from that," Tim Kupferschmid, executive director of Sorenson Forensics, said Thursday.

West Valley police have said they believe the pieces of wood may have been used to burn human remains, though it is unclear whose remains they might be. Three different sets of trained cadaver dogs independently indicated last week that they detected human decomposition on the pieces, investigators said.

Kupferschmid said there is a concern about how much the DNA has degraded, but it will not result in misidentification.

"No chance in the process does the DNA degrade and turn into someone else's DNA," Kupferschmid said. "It's either going to be a match or you're going to get no results or inconclusive results."

The process, he said, is really no different than any other DNA sampling — though trying to extract a DNA sample from a charred piece of wood in itself is a rare event. Technicians still follow the same basic steps of extracting the sample, determining how much is there, copying and growing the sample, and then detecting it. "It's completely reliable," Kupferschmid said.

Similar scenarios with charred remains, he said, come into play occasionally in airplane crashes and car accidents.

Another thing experts can determine from charred wood is whether an accelerant was used.

"Gasoline or lighter fluid or something like that," the director said. "That could possibly be used to (determine whether) the same accelerant was found on the perpetrator's car, or what have you."

Powell, 28, was last seen on Dec. 6, 2009. Late that night, husband Josh Powell said he took their two young boys camping on a very cold night near Simpson Springs, about 25 miles away from the Topaz Mountain area. Josh Powell has been called a person of interest in the case because West Valley police say he has been very uncooperative.

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