Sheriff says he believes Nancy Guthrie kidnapper could strike again

Over a month after Savannah Guthrie's 84-year-old mother was abducted from her Arizona home, the sheriff in the case is providing details on a possible motive.

On Thursday, March 12, Pima County Sheriff Chris Nanos told "NBC Nightly News" that he believed Nancy Guthrie's kidnapper could strike again. The case of the "Today" show host's missing mother has captured national attention, after she was reportedly taken against her will in the early morning hours of Feb. 1. An exhaustive search for both her and her abductor has since swept across Arizona, while the Guthrie family has released direct pleas to the suspect.

"We believe we know why he did this, and we believe that it was targeted," Nanos told NBC correspondent Liz Kreutz. "We're not 100% sure of that, so it would be silly to tell people, 'Yeah, don't worry about it, you're not a target.'"

"Don't think for a minute that because it happened to the Guthrie family, you're safe. No, keep your wits about you," he continued. "From day one, we had some strong beliefs about what happened, and those beliefs haven't diminished."

The investigation into Guthrie's disappearance has looped in old-school DNA leads and newer technology to surface images of the alleged suspect from a doorbell camera in front of the elderly woman's home. Private companies, working with local police and the FBI, were able to retrieve footage of a masked and armed man approaching Guthrie's home the night of the kidnapping.

Nanos also told NBC that they're looking into a potential Wi-Fi jammer being used to interrupt Guthrie's internet service the night of the crime.

When was Savannah Guthrie's mom Nancy, last seen?

Nancy Guthrie has not been seen since Jan. 31, and her family reported her missing the following morning.

After she failed to show up at a friend's house to watch a church service online on Feb. 1, as she routinely did, they called her daughter, Annie, who lives nearby, a source close to the family told NBC News.

Nancy Guthrie abduction timeline

In a press conference on Feb. 5, Pima County Sheriff Chris Nanos told reporters that doorbell camera video had helped authorities piece together a timeline of Guthrie's kidnapping.

• Jan. 31 at 5:32 p.m. Guthrie traveled to her family's house for a game night.
• Jan. 31 at 9:48 p.m. Her family dropped her back at home, and the garage door opened.
• Jan. 31 at 9:50 p.m. The garage door closed.
• Feb. 1 at 1:47 a.m. Doorbell camera in front of Guthrie's home disconnected.
• Feb. 1 at 2:12 a.m. Software for the smart home detected a person on the camera.
• Feb. 1 at 2:28 a.m. Guthrie's pacemaker app shows it was disconnected from her phone.
• Feb. 1 at 11:56 a.m. The family checks on her.
• Feb. 1 at 12:03 p.m. Family calls 911 to report her missing.
• Feb. 1 at 12:15 p.m. Patrol cars arrive.

Contributing: Brendan Morrow, USA TODAY; Richard Ruelas and Sarah Lapidus, Arizona Republic