A new type of DNA test — Y-STR DNA testing — being used by the Tulsa OK police is breaking tough sexual assault cases in which minimal quantities of genetic material are available for laboratory testing, Tulsa TV station FOX23 Mediacenter says. “It’s excellent in cases where you wouldn’t have anything else to do otherwise,” said Valerie Fuller, a forensic specialist for the Tulsa police. “You would never want to use this test as a first round DNA testing.”
The method has already been successfully used to prosecute rapist Gary Lee Graham in a case in which the DNA information for two victims was too weak to use in conventional testing. The test takes only two months to complete. The downside is, the test provides matches of only about 1 in 4,000 cases — far less certainty than conventional DNA tests. “It’s not an exclusion, but it’s not as great a number as juries are used to hearing,” Fuller told FOX23.