Nancy Guthrie was last seen on Jan 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.
The sheriff has said the doorbell camera was disabled shortly before her pacemaker app lost its connection with her telephone line early on Feb 1.
That and the fact that Guthrie lacked the physical mobility to wander off far from home unassisted led investigators to conclude early on that she had been taken against her will, Nanos said.
Law enforcement and family members have described her as being in frail health and in need of daily medication to survive.
Traces of blood found on her front porch were confirmed by DNA tests to have come from Guthrie, officials said last week.
On Friday, the sheriff’s office said DNA from people other than Guthrie or “those in close contact to her” has also been collected from her property, and investigators are “working to identify who it belongs to”.
Several discarded gloves found during the investigation, including some found roughly 2 miles from Guthrie’s home, were undergoing forensic analysis, the department said.
“HOPE IS SOMETIMES ALL WE HAVE”
Nanos also defended what he called a joint decision with local FBI leaders to send all physical evidence in the case to the same Florida laboratory – a longtime contractor with his agency and one used since the start of the investigation – to “ensure consistency and streamline testing”.
At least two purported ransom notes have surfaced since she disappeared, both delivered initially to news media outlets and setting two deadlines that have since lapsed.
Savannah 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 expressing a willingness to meet ransom demands.
Nanos told Reuters that no proof of life has surfaced since the abduction but he was quick to add: “There’s not been any proof of death either.” He said his working presumption is that Nancy Guthrie remains alive.
“Hope is sometimes all we have, it really is,” he said.
“I have a team of 400 officers from federal government, state government, local government. I have a community of a million people here who are invested in this, who want her back. Sometimes all we have to go on is hope. I’m not going to kill that.”
