New Delhi, Feb. 8 -- A week after Nancy Guthrie, the 84-year-old mother of NBC "Today" show anchor Savannah Guthrie, was last seen, authorities continue to search for her.

Nancy Guthrie was last seen on the night of January 31 when she was dropped off at her Tucson home by her daughter Annie and son-in-law. The following morning, she failed to attend church, prompting relatives to check on her around noon February 1, only to find her missing.

Investigators say her video doorbell and pacemaker app disconnected overnight, and while the doorbell detected movement around 2 a.m., any recorded footage was not saved. Blood found on the front steps of her home was later confirmed to be hers.

Authorities have stressed that Nancy Guthrie is in p...