Troyer seemed eager to talk about her discovery, which still had her puzzled, Barlow recalled. The analyst told Barlow she had searched the growing Arizona database since the conference and found more pairs of profiles matching at nine and even 10 loci.
Encouraged, Barlow subpoenaed a new search of the Arizona database. Among about 65,000 felons, there were 122 pairs that matched at nine of 13 loci. Twenty pairs matched at 10 loci. One matched at 11 and one at 12, though both later proved to belong to relatives.
Barlow was stunned. At the time, such matches were almost unheard of.
That same year, Fred Bieber, a Harvard professor and expert in forensic DNA, testified in an unrelated criminal case that just once had he seen a pair of profiles matching at nine of 13 markers, and they belonged to brothers. He had heard of a 10-locus match between two men, but it was the result of incest -- a man whose father was also his older brother.
Indeed, since 2000, the FBI has treated certain rare DNA profiles as essentially unique -- attributable to a single individual "to a reasonable degree of scientific certainty."
Other crime labs have adopted the policy, and some no longer tell jurors there is even a possibility of a coincidental match.
Soon after Barlow received the results, Callaghan, the head of the FBI's DNA database unit, reprimanded Troyer's lab in Phoenix, saying it should have sought the permission of the FBI before complying with the court's order in the San Francisco case.
Asked later whether Callaghan had threatened her lab, Troyer said in court, "I wouldn't say it's been threatened, but we have been reminded."
Dwight Adams, director of the FBI lab at the time, faxed Griffith, Troyer's boss, a letter saying the Arizona state lab was "under review" for releasing the search results.
"While we understand that the Arizona Department of Public Safety, acting in good faith, complied with a proper judicial court order in the release of the nine-loci search of your offender DNA records, this release of DNA data was not authorized," Adams wrote, asking Arizona to take "appropriate corrective action."
Arizona officials obtained a court order to prevent Barlow from sharing the results with anyone else.
But it was too late. After a judge found the Arizona results to be irrelevant in Barlow's case, the defense attorney e-mailed them to a network of her colleagues and DNA experts around the country.
