Gunshot residue may be key to case

Police have stated several reasons why they think Lisa Barlow was lying in interviews immediately following the shooting death of her boyfriend.

But police have yet to establish a clear motive. A weapon has not been found, and police have not shared evidence showing that Barlow actually pulled the trigger that killed Michael Strong.

But more evidence could be forthcoming. Police have stated that a gunshot residue test was performed. They said the results were not ready by the time police prepared the probable-cause statement.

The result of the test may play a key role for either the prosecution or defense. The evidence will eventually be shared in court proceedings, which begin with a 9 a.m. arraignment today at the Bollinger County Courthouse.

Barlow faces first-degree murder charges.

The evidence against Barlow includes blood spatter analysis, statements from a neighbor who heard the gunshot and interviews with her most-recent ex-husband.

All of it serves to poke holes in the story Barlow told police, that at 11 p.m. July 27, she was sleeping in bed and awakened by Strong telling someone to "get out," followed by a gunshot.

When the details of the test are brought into a courtroom, they could show Barlow handled a recently fired gun, casting doubt on her statements that she hid under the bed and called 911 when she heard Strong arguing with intruders.

Gunshot residue tests alone are not typically enough to convict a person. However, they can be used to strengthen cases and catch suspects in lies.

That was the situation in a 1994 case in Cape Girardeau when a gunshot residue test helped convict John Wes Selvy in the shooting death of his 15-year-old girlfriend Shekelia Johnson.

The test showed particles of gunshot residue still clung to Selvy's hands, tainting his story that Johnson took her own life.

In cases like Selvy's where gunshot residue analysis contradicts a defendant's story, it can be a valuable piece of corroborating evidence, said Cape Girardeau County Prosecuting Attorney Morley Swingle.

Gunshot residue testing probably played the biggest role in Selvy's case of all of those Swingle has tried in his 20-year career, he said.

While the analysis cannot prove beyond reasonable doubt that someone fired a gun recently, it can indicate they've handled one after it was discharged, explained Jenny Smith, a trace evidence criminalist for the Missouri State Highway Patrol Crime Lab in Jefferson City, Mo.

"If someone shows up with a positive test, and denies all association with guns, and if we find a bunch of [residue] on his hands, I guess he would have some explaining to do," Smith said.

Barlow told police that guns were dirty and she did not like them, but two of Strong's relatives said he had recently let her fire his. 44-caliber Magnum at cans in the backyard, and she was a good shot, according to the probable-cause statement written by Cape Girardeau County Chief Deputy Lt. David James.

When someone fires a gun, the firing pin hits the bullet, setting off a spark and producing enough heat and pressure to set off the explosive salts within the barrel of the weapon.

The gases mix to form a plume around the gun, and when they cool, they become spheres. Those spheres make up what are commonly known as the gunshot residue particles.

Scientists look for three types particles when they examine gunshot residue evidence: antimony, lead and barium. All three elements are considered characteristic of gunshot residue but separately they are not unique enough to be called a positive test result, said Smith.

Because lead is so common in the environment, and barium and antimony are often found in fireworks, it is possible that other activities could cause one or two of the elements to appear on someone's hands, according to John C. Ceyton, a criminalist who operates an independent forensics lab in Osborn, Mo.

"We've had [results] come back where there will only be two of three, and the expert is usually unwilling to say the results are consistent with someone who has recently fired a gun," Swingle said.

Educating the jury on the strengths and limitations of gunshot residue testing is the primary job of the expert witness testifying about the test, said Smith, who testifies about 10 to 12 times per year in these types of cases.

Smith explains to juries that although crime analysts are extremely adept at detecting these particles, they can't always tell for certain how they got there.

"The devil is in the interpretation," Smith said.

When presented to a jury, gunshot residue evidence may seem fairly incriminating.

"Talking about the cloud of gun smoke getting on your hands, showing photographs of it, really helps the jury understand," Swingle said.

While gunshot residue can be a valuable piece of supporting evidence, it generally is not used to prove an entire case, Swingle and Smith both said.

"I think it should always be corroborative and interpretative in light of all the other available evidence," Smith said.

bdicosmo@semissourian.com

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