"Extremely low levels" of DNA in a 2009 Buckeye rape case made for a difficult analysis, leading to a long delay for the results, says the state's crime lab supervisor.
Although a 14-year-old victim found the courage to report the rape two days after it occurred in April of 2009, police didn't identify a suspect for another year. A DNA sample on the suspect, 36-year-old Phonesavanh Nakhokkong, was submitted to the Arizona Department of Public Safety in May of 2010.
Lab workers just finished the analysis last week, and the test results spurred cops to make an arrest.
Todd Griffith, who oversees the DPS crime-lab system, says the case proved to be "very complex and difficult."
Typically, DNA tests submitted to DPS in homicide and sexual assault cases get completed within a month, he says.
True, Griffith explains, recent budget cuts have meant that DPS' crime lab system operates with about 20 percent fewer employees than would be ideal. But DNA analysis of violent crime cases these days isn't routinely backed up.
DNA analysis for burglaries -- that's another story. DPS crime labs have about 3,000 burglary cases "backlogged," with some pending for more than a year, Griffith says.
"We prioritize our DNA cases," he says. "Sexual assaults, homicides -- we can pretty much start those when they come in the door."
The Nakhokkong case, though, was "unique."
The victim went to police on April 28, 2009, claiming she'd been raped in a Buckeye park two days before. She'd gone there to drink booze with two teenage friends and some adult men.
"That could be considered a bad decision on her part," says Buckeye Detective Joseph Kirby, who investigated the case.
The men were friends of one of the other girls. The victim told police that after she became "highly intoxicated," Nakhokkong forced himself on her despite her repeated protests. She woke up the next day without a bra or underwear, and with suction marks on her breasts. But she didn't submit to a forensic exam until a day later.
That exam showed evidence of forced sex. Swabs were taken from the girl's body and placed into an evidence locker.
Kirby says all police knew for a while was that the alleged attacker went by the name of "Sam."
The girl's so-called friends didn't prove to be very cooperative.
"We were getting very little info from the girls who were there," Kirby says. "Nobody wanted to say who was who."
After a number of interviews with potential suspects and the girls' family members, Kirby finally located "Sam" in April of 2010. The man freely offered to give up a DNA sample, but Kirby had a court order drawn up regardless, just to make sure it got done promptly, he says.
He hasn't talked to the girl lately, but says "I'm sure there's some frustration" with the time lag.
Lab workers who made the initial tests discovered traces of DNA from the swabs, but nothing conclusive. Some of the "latest and most sensitive techniques" were used over the following months to coax results from the minimal evidence, Griffith says.
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He doesn't want to get into the specifics of the work done in the Nakhokkong case, but describes how the state's four labs (Phoenix, Tucson, Flagstaff and Lake Havasu City) uses state-of-the-art technology.
Besides the traditional, OJ Simpson-type DNA analysis, the labs also can analyze DNA from male chromosomes and the maternally passed-on mitochondrial DNA. Arizona has one of only three labs in the country that have partnered with the FBI to conduct mitochondrial DNA analyses, he says.
A regular DNA analysis costs the state about $2,400, while the mitrochondrial kind -- paid for by the feds as part of the agreement -- costs about twice that, Griffith says.
The state's four labs conducted more than 6,300 DNA analyses from July 2010 to June 2011.