- Publication: Athens Daily News
- Author: Joan Stroer, Staff Writer
- Original Publication Date: Friday, April 23, 1993
In 1986, the first use of DNA analysis in a criminal case was against a mentally unstable 17-year-old Englishman, accused of raping and killing a 15-year-old, then leaving her body to decompose in a field.
When results came back, he was freed.
“DNA is a great tool but it’s not going to solve all the cases for you,” Oconee County Sheriff Scott Berry said.
In 1991, Berry helped the Clarke County District Attorney’s Office convict rapist Jerry Muckle in the first case here to use the microscopic evidence. “DNA goes to identification or lack of identification,” he said.
That’s a double-edged reality Athens-Clarke police detectives know well, having run the test on about 40 suspects in the strangulation slaying and rape of Jennifer Stone. None had a DNA profile which matched her killer’s.
Since January 1991, six workers at the GBI State Crime Lab have battled the clock in a large room on the complex’s top floor, running about 40 of the time-consuming tests a month. It takes up to 75 days for a tissue sample to be broken down and analyzed, GBI spokesman John Bankhead said.
“I don’t look at it as ‘this could be the suspect,’ ” GBI technician Stephen DeJesus said recently while analyzing blood from a suspected rapist. “I just test what I’ve got.”
The process workers use, commonly called DNA fingerprinting, can pinpoint a suspect with almost 100 percent accuracy since the DNA of every person is distinct. Only identical twins have matching DNA.
DNA, or deoxyribonucleic acid, is a genetic code found in the nucleus of every body cell that determines one’s physical characteristics.
The substance can be extracted from blood, semen or tissue found at a crime scene. It’s then broken into fragments by enzymes, and the particles are separated magnetically to form dark bands.
Ultimately, the fragments form a “bar code” on an X-ray sheet which can be compared with another person’s DNA pattern. From the comparison, experts generate odds on how close the two patterns may match.
[Graphic] DNA Fingerprinting Technique (Janet Beckley / Staff)