A look at all the videos from Nancy Guthrie's family since her disappearance

PHOENIX — ''Today'' show host Savannah Guthrie and her siblings have posted a series of videos on social media since the disappearance of their mother, 84-year-old Nancy Guthrie, in a mysterious case that has gripped the nation.

The family's Instagram videos have shifted in tone from impassioned pleas to whomever may have their mom, saying they want to talk and are even willing to pay a ransom, to bleaker and more desperate requests for the public's help. The latest video on Thursday was simply a home video of their mother and a promise to ''never give up on her.''

The FBI has said it's unaware of ongoing communication between Guthrie's family and any purported kidnappers. This week, the agency released the first surveillance video of a masked person who authorities said appeared to tamper with a camera on Nancy Guthrie's front door the night she went missing. The FBI said Thursday the person is a male about 5-feet, 9-inches tall who they now consider to be a suspect.

Savannah Guthrie quickly posted the images and called on the public to reach out to law enforcement with any information.

Here is a timeline of the videos the family has posted:

Feb. 4

Savannah Guthrie acknowledged alongside her siblings that their family was aware of media reports of a purported ransom letter and that they were ready to talk and listen, but they wanted proof their mother was alive. They spoke directly to their mother. ''Mommy, if you are hearing this, you are a strong woman, you are God's precious daughter, Nancy,'' Savannah Guthrie said.

Camron Guthrie, on behalf of the Guthrie family, said they had not heard anything directly from whoever took Nancy Guthrie. He said the family wanted to talk but was waiting for contact and needed a way to communicate in order to move forward. He also said they needed proof from whoever took their mother.

Feb. 7

Holding hands with her siblings, Savannah Guthrie they received a message and ''understand'' without providing any details. She said they were begging for their mother to be returned to them. ''We will pay,'' Guthrie said.

Feb. 9

Savannah Guthrie said her family was at an ''hour of desperation'' and they believed Nancy Guthrie was still out there. She asked not only for prayers but help, calling on the public to report anything they see or hear to law enforcement. No ransom note was mentioned, despite a purported deadline set for that evening.

Savannah Guthrie posted surveillance images and video released by the FBI of an masked person with what appeared to be a handgun holster at the waist. The images are from the night Nancy Guthrie went missing. The person covered a camera with a gloved hand before placing plants over it.

A second post from Savannah Guthrie implored anyone with information on her mother to reach out to authorities. ''Someone out there recognizes this person,'' she said. ''We believe she is still out there. Bring her home.''

Feb. 12