In the grainy video recovered from an ageing doorbell camera in Tucson, Arizona, the man moves with eerie calm. Mask on, gloves pulled tight, a heavy backpack tugging at his shoulders, a gun riding his waistband.

He pauses just long enough to shove yard clippings over the lens, then disables the device and disappears from view.

Somewhere beyond that narrow frame, 84-year-old Nancy Guthrie — mother ofTodayco-hostSavannah Guthrie— vanishes.

For investigators, that clipped fragment of footage has become both a lifeline and a tormenting reminder of what they still don't have. And now, the man in charge of the search is warning that the chances of extracting anything more from Nancy's smart-home cameras are fading fast.

New images in the search for Nancy Guthrie:Over the last eight days, the FBI and Pima County Sheriff’s Department have been working closely with our private sector partners to continue to recover any images or video footage from Nancy Guthrie’s home that may have been lost,…pic.twitter.com/z5WLgPtZpT

Pima County Sheriff Chris Nanos has been blunt, even a little brutally honest, about the state of the hunt for more video.Google technicians, he says, have been 'trying' for days to salvage extra footage from Nancy's Nest devices — but hope is thinning.

An internet-connected Google Nest camera captured an unidentified person in a mask and gloves and carrying a backpack and a gun approaching Nancy Guthrie’s home just before she disappeared. FBI...

The problem is punishingly simple. Nancy, who was abducted from her Tucson home in the early hours of 1 February, did not pay for a Nest subscription. Without it, the cameras in and around her house did not continuously record video to the cloud.

In ordinary circumstances that's an irritating quirk of a tech service model. In a kidnapping case, it is a gaping hole.

After more than a week of work, Google's engineers finally coaxed a few seconds of usable footage from the front doorbell camera, enough to show the masked suspect tampering with and then removing the device. The FBI released that clip on 10 February with the kind of urgency that signals there isn't much else to go on.

Source: International Business Times UK