In an unusual feat of laboratory sleuthing, Purdue University scientists solved the case of a stolen black walnut tree by using DNA analysis to match two logs sold to a lumber mill to a tree stump more than 60 miles away.
"This DNA technology put the log back on the stump," said Keith Woeste, a molecular geneticist at Purdue's Hardwood Tree Improvement and Regeneration Center.
Woeste believes this is the first time a tree-poaching case has been solved using the same genetic tests used in criminal cases such as rapes.
The case began in November when an incensed landowner in western Indiana's Warren County contacted the Indiana Department of Natural Resources after finding the stumps and chainsawed branches of a black walnut tree and a black cherry tree on his property.
Indiana conservation officers began investigating the two stolen trees, focusing on the 55-foot-tall black walnut tree, which was worth at least $2,500 to furniture makers who covet its fine, dark wood.
Conservation officer Don Dyson said he and his colleagues found tracks from machinery alongside the two tree stumps.
They quickly determined that a timber-cutting crew had been cutting trees on contract on adjacent property at the time the trees well across the property line vanished. Their investigation led to a lumber mill in the city of Peru about 60 miles to the northeast where the state-licensed timber-cutter in question routinely sells trees he harvests.
There, Dyson found two large black walnut logs awaiting their date with the mill's saws that appeared to match the missing tree's description.
Slices that had been taken of the black walnut's stump and shorn off crown closely matched the ends of the two walnut logs, but it wasn't a slam-dunk.
"We thought we had a match but we weren't 100 percent sure. We weren't ready to go to court," Dyson said.
A state forester assisting with the investigation then mentioned that Purdue's Hardwood Tree Improvement and Regeneration Center regularly performs DNA tests on trees as part of the research there.
The DNR employees met with Woeste, who agreed to assign four students to perform a genetic analysis technique called DNA fingerprinting to compare the confiscated log's DNA to that of the stump and branches.
Woeste said the students' analysis matched the various pieces of wood to such a high degree of accuracy that, like DNA evidence in a rape case, it would have been admissible in court.
Armed with the DNA match, Dyson presented the evidence to the licensed timber-cutter whose workers were suspected of cutting down the two trees.
The case was not prosecuted because the landowner agreed to settle out of court and the timber-cutter was eager to avoid a tree poaching conviction that could have cost him his state license.
"Once he found out all the evidence that we had he was more than willing to settle with the landowner," Dyson said. "That license is his livelihood."
The man paid the landowner more than $9,000 -- about three times the estimated value of the two trees. A state law allows property owners to recoup three times the value of a tree accidentally cut or purposely cut down by someone else, Dyson said.
He said most tree-poaching cases in Indiana go unreported or unprosecuted because landowners don't notice a tree has been felled and hauled away for years, if ever.