TUCSON, Arizona, Feb 17 (Reuters) - One of the most promising leads yet in the investigation into the abduction of Nancy Guthrie proved a disappointment on Tuesday when DNA from a glove found near her Arizona home failed to score a match in a national database of genetic profiles.
The outcome, announced by the Pima County Sheriff's Department and FBI, marked a major setback for investigators as the search for the 84-year-old mother of television journalist Savannah Guthrie stretched into its 17th day.
Investigators had hoped a DNA sample retrieved from the glove last week would produce what forensic experts call a "hit" when it was submitted for comparison with known DNA profiles stored in a national database called CODIS, short for the Combined DNA Index System.
The glove, found discarded in a roadside field about 2 miles from the elder Guthrie's Tucson-area house, resembled a pair worn by an armed man in a ski mask seen in video footage trying to disable her doorbell camera in the early morning hours shortly before she was abducted.
Sheriff Chris Nanos has said he believes the man in the video, who was also wearing an over-stuffed backpack and a handgun in a holster, is the likely perpetrator of the abduction and the primary suspect authorities are looking for.
'NO CONFIRMED CODIS MATCHES'
But the sheriff's department said on Tuesday that the glove DNA failed to trigger a match in CODIS or with DNA found at the Guthrie property.
"At this point, there have been no confirmed CODIS matches in this investigation," the sheriff's office said, adding that additional DNA evidence recovered at Guthrie's residence was still being analyzed. "CODIS is one option of many databases that are available," the agency said.
Guthrie's disappearance, treated by authorities as an apparent kidnapping for ransom, has drawn intense public interest around the globe, with news media outlets following every twist and turn in the case.
Much of the probe involved old-fashioned detective work, including investigators working with managers of Walmart retail outlets to pinpoint a person who purchased the backpack seen in the video, the sheriff's office said.
Phillip Martin, co-owner of a Tucson gun store, told Reuters on Tuesday that an FBI agent who acknowledged he was working on the Guthrie case visited his shop with a list of fewer than 20 potential customers and asked if any had purchased a weapon there. Martin said he checked but none had.
The visit to this gun shop was more than a week ago, and law enforcement continue to refine lists of potential persons of interest. The list being shown to gun stores was developed from cross-referencing backpack and holster purchases and other data points, a law enforcement official told Reuters.
In other efforts, the sheriff's department said its investigators had been using a "signal sniffer" technology that produces a heat map to identify potential search targets within a given area. Parsons Corp, which designed the system, said it has been used by search teams in the Guthrie case operating by helicopter, ground vehicles and on foot.
FAMILY RULED OUT AS SUSPECTS
Nancy Guthrie was last seen on January 31 when she was dropped off at her home near Tucson by her family after she had dined with them, and was reported missing by relatives the following day, authorities have said.
Nanos has said the elder Guthrie was extremely limited in her physical mobility and could not have left her home unassisted, leading investigators to conclude early on that she had been taken against her will.
At least two purported ransom notes have surfaced since she vanished, both of them delivered initially to news media outlets. There has been no known direct contact between any suspects and Guthrie's family or authorities.
Savannah Guthrie, 54, co-anchor of the popular NBC News morning show "Today," has posted several video messages, along with her brother Camron Guthrie and sister Annie Guthrie, pleading for their mother's return and appealing for the public's help in solving the case.
On Sunday, Nanos released a statement declaring that immediate family members - all siblings and their spouses - have been ruled out as suspects in the case, saying "The Guthrie family are victims, plain and simple."
Traces of blood found on Guthrie's front porch were confirmed by DNA tests to have come from Guthrie, officials said last week. Law enforcement and family members have described her as being in frail health and in need of daily medication to survive. She also has a pacemaker.
Nanos told Reuters last week that no proof of life has surfaced since the abduction, but added that "there's not been any proof of death either," saying his working presumption is that Nancy Guthrie remains alive.
(Reporting by Rebecca Noble in Tucson, Arizona; Writing and additional reporting by Steve Gorman in Los Angeles; Additional reporting by Jana Winter and Jasper Ward in Washington and Herbert Villarraga in Tucson; Editing by David Gregorio and Stephen Coates)
