City Desk

What Wipe Marks? Defense Expert Disputes Knife Evidence in Robert Wone Case

Robert Wone PostersDefense attorneys for three men accused of conspiring to cover up the 2006 murder of D.C. attorney Robert Wone called their first witness Thursday after four weeks of witness testimony for the prosecution.

On the stand, forensics expert Nicholas Petraco disputed prior testimony from former O.J. Simpson-trial expert Douglas Deedrick, who had earlier suggested that blood patterns and fibers on the knife found next to the murdered attorney indicated the bodily fluid had been wiped onto the weapon.

Looking at the same photos of the knife, Petraco took issue with Deedrick's analysis. "I've done lots of different impression evidence, including textile," said Petraco. "I really don't see a pattern. I see some droplets of blood."

Prosecutors have accused defendants Joseph Price, Dylan Ward and Victor Zaborsky of perhaps substituting a second knife in place of the actual murder weapon in an alleged attempt to confuse investigators. The three lovers and housemates, who contend an unknown intruder broke into their home at 1509 Swann Street NW and fatally stabbed their friend Wone, stand accused of conspiracy and obstruction of justice in connection to Wone's death. Earlier Thursday, a judge dropped additional evidence-tampering charges against Ward and Zaborsky, but not Price.

On the stand, defense witness Petraco also criticized Deedrick's authority on the matter, considering that the prosecution witness had never personally visited the crime scene and based his findings on photos of the evidence. "It's very important if possible to get to the crime scene," Petraco said. "It helps you read the story that's being told." (Of course, Petraco hadn't been to the crime scene, either.)

Petraco also disputed Deedrick's distinguishing between two supposedly different fibers found on the knife: one type from Wone's white t-shirt and another from a white towel that the prosecution believes the conspirators may have used to dab Wone's blood onto the knife.

Asked if he could tell any difference, Petraco stated, "No, they pretty much looked like what you'd normally see with colorless cotton fibers."

Photo by Darrow Montgomery

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  • Rick Mangus

    You can have five experts and get five opinions!

  • TomDC

    Actually the prosecutor's expert Deetrick said much the same; that cotton fibers are colorless and pretty much everywhere. He also said fiber-transfer was not a reliable science and usually not good evidence. Yet the judge admitted his evidence including his disclaimers.

    Prediction: the knife decides the case one way or another.

  • Sa Wardja

    What the article didn't say was one important thing--the prosecutor asked Petraco what the t-shirt was made up of, and he said 99% cotton, 1% rayon. When asked if he found any rayon fibers, he said he did not (even at 1%, it is expected that there would be some rayon fibers, which are distinctly black). Petraco offered that he was "surprised" he didn't find any (of course, there's no "surprise" if the fibers were from the towel, rather than the shirt, in which case one would not expect to find rayon fibers, as was the actual case). It seems like he negated his own testimony to me.