The transfer of gunshot residue between two suspects in the October 2009 slaying of an Iowa City landlord drew sharp questioning from attorneys on Jan. 25.
One of the suspects, 20-year-old Justin Marshall, is on trial this week, charged with first-degree murder in connection with the Oct. 8, 2009, killing of John Versypt.
During proceedings, Iowa City police Sgt. Dave Droll recounted packaging the evidence after the homicide. But other officers’ actions led Thomas Gaul, Marshall’s attorney, to repeatedly ask Droll about the possibility of residue transfer.
“In this case, you didn’t collect the evidence yourself?” Gaul asked Droll. “If officers contaminated it, you wouldn’t even know that, would you?”
Gaul sought to draw a link between the clothing of Marshall and Charles Thompson, who lived in the same apartment in the Broadway Condominiums at the time of slaying.
Thompson was previously accused of killing Versypt, but a mistrial led him to accept a plea deal with lesser charges and to sign documents stating Marshall killed Versypt.
Assistant Johnson County prosecutor Meredith Rich-Chappel began her response to Gaul’s questioning by having Droll iterate he was not an expert on gun residue. But experts said they believe it is possible for a transfer to occur.
Steven Howard, a weapons and gunshot residue expert from Lansing, Mich., said the substance — a mixture of lead, barium, and antimony — exits a gun upon its firing. Gunshot residue is unique, Howard said, because those three chemicals “almost never” occur naturally together and never break down.
“Under very specific conditions, [gunshot residue] can eliminate suspects or indict the guilty,” Howard said. “It’s one of those things where, if it’s there, it’s like ‘so what,’ but if it isn’t, that means something.”
Howard said it is “plausible” for gunshot residue to be transferred between suspects, but “100 other things are plausible,” including an officer transferring residue to a suspect.
“Unless they can isolate these questions and answer them, it’s of no meaning at all,” Howard said.
“If you have two individuals, the one with strong gunshot residue on his hands would be a more interesting person to talk to than a person who just had a flake or two on clothing and none on the hands,” Leisinger said.
In general, Howard said gunshot residue should be used as evidence carefully.
“[Law enforcement] is either overusing it or not using it all,” he said. “They say it’s so unreliable. Well, it is reliable but only under certain circumstances.”
In addition to discussion about gunshot residue, Jonathan Thompson, an associate medical examiner for the state of Iowa, testified about bullet wounds Versypt suffered to both his right hand and forehead. He said the gunshot to Versypt’s forehead was the cause of his death.
Thompson later said injuries to Versypt’s pinky finger, among other indicators, would be consistent with him trying to put his hand around the revolver before he was shot.
Droll later testified officials with the Bureau of Alcohol, Tobacco, Firearms, and Explosives were unable to find the origin of the revolver found near Versypt. That added to complications because authorities were unable to gather fingerprints from the crime scene.
The trial is scheduled to end this week, and it will continue this morning. Johnson County prosecutor Janet Lyness said she hopes to finish presenting witnesses on Wednesday. Marshall faces life in prison if he is convicted.