By Erica Stapleton and Jana Winter
TUCSON, Arizona, Feb 11 (Reuters) - Sheriff's deputies and FBI agents fanned out along highways, vacant lots and remote dwellings of southern Arizona on Wednesday, combing the desert landscape for clues to the fate of U.S. television journalist Savannah Guthrie's abducted elderly mother.
As the search for 84-year-old Nancy Guthrie stretched into its 11th day, a law enforcement official briefed on the case told Reuters that investigators were running forensic tests
on a newly discovered black latex glove, looking for fingerprints and possible DNA samples.
The New York Post on Wednesday posted video and photos of FBI personnel taking possession of a glove they had found discarded on a roadside about 1.5 miles from the elder Guthrie's home, where she was presumed kidnapped for ransom.
It was not clear whether the glove collected as evidence matched the pair worn by an armed man in a ski mask seen in video footage authorities released on Tuesday showing the unknown intruder tampering with Guthrie's doorbell camera at about the time police say she was taken.
Nancy Guthrie was last seen on January 31 when family dropped her off at her home following an evening dinner with them, and relatives reported her missing the following day, authorities said.
PEERING THROUGH THE MASK
As police and forensic analysts on foot scoured a search zone on the outskirts of Tucson seeking more physical evidence, the law enforcement official said the newly released video was undergoing "advanced analytics" in an effort to produce a better glimpse of the masked stranger in the images.
Investigators are "likely attempting to identify facial features/markers through the fabric" of the ski mask, a former FBI agent explained. "This can be done using special mathematical techniques and potentially AI given recent advancements in the field.”
Techniques involve measuring the shape of and distance between a person's eyes, ears, mouth, nose, jaw, cheeks and forehead to establish a facial geometry that can be fed through databases in search of a match.
Pima County Sheriff Chris Nanos has said the elder Guthrie had extremely limited mobility and could not have wandered off far from home unassisted, leading investigators to conclude early on that she had been abducted by force.
THOUSANDS OF TIPS
Traces of blood found on her 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.
At least two purported ransom notes have surfaced since Nancy Guthrie vanished, both of them delivered initially to news media outlets and setting two deadlines that have come and gone. But no proof of life is known to have surfaced following her abduction.
Guthrie, 54, co-anchor of the popular NBC News morning show "Today," has posted several video messages with her brother and sister, appealing to their mother's captors for her return, pleading for the public's help in solving the case, and even asserting a willingness to meet ransom demands.
An apparent break in the case came late on Tuesday when the sheriff's office announced that a "subject" of the investigation had been detained for questioning following a traffic stop in Pima County. But the person taken into custody was later released without being charged.
The sheriff's department also said that its deputies and an FBI forensic team conducted a court-authorized search of a "location" in Rio Rico, Arizona, about 60 miles south of Tucson near the Mexico border. The man who said he was detained told reporters he lived at the address that was searched.
Hundreds of sheriff's deputies and FBI agents have been assigned to the case, receiving nearly 18,000 phone tips since February 1, more than a quarter of those within the last 24 hours, the sheriff's office said on Wednesday.
(Reporting by Erica Stapleton in Tucson, Arizona and Jana Winter in Washington; Writing and additional reporting by Steve Gorman in Los Angeles; Editing by Kate Mayberry)
