A 4th District Court judge is expected to decide this week whether to allow DNA-identification test results as evidence in the trial of a West Valley man accused of killing his ex-wife and setting her body on fire.
Prosecutors want to use DNA-matching test results to prove that bodily fluid found on Shelly Ann Jiron's body came from her ex-husband, Joe Jiron. They allege Joe Jiron, 24, asphyxiated Shelly Jiron, 22, on the west side of Utah Lake on Dec. 17, 1991.Attorneys for Joe Jiron are trying to keep the DNA-matching results out of their client's trial. During a hearing Monday, Judge Cullen Y. Christensen heard testimony about the testing; he was expected to hear more testimony Tuesday before ruling whether to allow the results as evidence.
Charlotte Word, a molecular geneticist with Cellmark Diagnostics of Germantown, Md., said four different regions of the DNA in Joe Jiron's blood matched that of DNA in the fluid recovered from his ex-wife's body.
Four to five matches, she said, approaches "virtual identity" of an individual.
"I think it's highly unlikely that there would be another individual with this DNA-banding pattern," Word said.
Joe Jiron's attorney, John Musselman, objected to deputy county attorney Phil Hadfield's move to admit the test results as evidence. Musselman spent Monday afternoon exploring factors that could lead to false positive results in DNA matching.
Two false positive tests were detected during a routine proficiency tests at Cellmark in 1987 and 1988. In the former test, one of 47 samples was mismatched. In the latter test, one of 50 samples proved wrongly positive.
Word, who joined the company in April 1990, attributed the first to human error, the second to a procedural error. Cellmark did not catch the mistakes before the test results were sent out.
Musselman argued that had those tests been conducted for a criminal case, a Cellmark scientist could have testified in court that those results were correct when in fact they weren't.
Word said that isn't likely to happen because procedural safeguards the company implemented would prevent it. In addition, she said, scientists are commonly assigned to only four to five forensic samples at a time, not 50 as in a proficiency test. Scientists are more intimately involved and follow more closely true forensic tests, Word said.
Subsequent proficiency tests have yielded no errors, Word testified.
The defense, however, was successful in preventing Hadfield from entering as evidence a list of states in which Cellmark had testified about DNA testing. Mus-sel-man said what has been done in other states wasn't relevant. He said DNA testing may be accepted by the scientific community, but that doesn't mean the legal community has taken to it.
Christensen said the information wouldn't be helpful to him in deciding whether to allow DNA test results in this case.
Joe Jiron's trial is scheduled to begin Oct. 5. Beside ruling on whether to suppress the DNA matching results, Christensen will rule on whether to allow as evidence statements made by Joe Jiron to emergency workers, statements made by his current wife to police and a love letter found in Shelly Ann Jiron's car.