With few new leads 45 days after Nancy Guthrie's disappearance, investigation "becomes much harder," expert says

Nancy Guthrie has been missing for 45 days, and with the latest update in the case being of little use to authorities, one expert tells CBS News the extended timeline means it "becomes much harder to keep the investigation going."  In:

Nancy Guthrie has been missing for 45 days, and with the latest update in the case being of little use to authorities, one expert tells CBS News the extended timeline means it "becomes much harder to keep the investigation going." 

Law enforcement sources told CBS News that additional images were obtained in the last couple of weeks from surveillance cameras installed at Guthrie's Tucson home, where she is believed to have been abducted from in the middle of the night on Feb. 1.

The images, taken from a camera fastened to a fence and focused on the back of the house and another that showed the driveway and front of the garage door, captured family members, landscapers and pool workers stretching back weeks prior to the kidnapping. Nothing was deemed suspicious, and no images reviewed showed the suspect captured on the front door camera. 

In the seventh week of the investigation into the disappearance of the 84-year-old mother of "Today" co-host Savannah Guthrie, doorbell camera video shared by the FBI on Feb. 10 remains the only known images of the suspect.

Lance Leising, a retired FBI supervisory special agent, told CBS News it all points to "a lack of meaningful leads. That's the initial thing it says to me."