Image source, PIMA COUNTY SHERIFF

We have just heard from Pima County Sheriff Chris Nanos and Jon Edwards, the FBI's special agent in charge in Tuscon, Arizona, on the status of the investigation into Nancy Guthrie's disappearance.

The media briefing had little new information, but Sheriff Nanos says the scene at Guthrie's home has been thoroughly searched and DNA samples are being processed.

He says Guthrie was dropped off at her home on Saturday evening but when she didn't turn up at church the following day, it raised concerns. Relatives went to the house to check on her but she was not there.

Nanos says the sheriff's department is working with state and federal law enforcement agencies to help find the 84-year-old mother of NBC journalist Savannah Guthrie.

The FBI's Edwards says they are looking at all angles including cell phone records but adds that authorities need the public's help with informational tips that could help locate the missing woman.

We are ending our live coverage here but you can read more of our reporting on this story here:

• NBC anchor Savannah Guthrie's mother abducted, blood found in her home, authorities say

We've just heard from Pima County, Arizona Sheriff Chris Nanos.

On Monday, he told the BBC's US news partner CBS that authorities don't believe that Nancy Guthrie "willingly" left her home.

Image source, Reuters

Nanos says "it is a process" to get video from Guthrie's security cameras and and that authorities are working to get those videos as soon as they can.

"It's tough," he says.

Nanos then ends the news conference, adding that he knows the media has a job to do, "but we have a job to do too".

He says unless "something breaks", the next news update will be on Thursday.

With that, the news conference has ended.

Sheriff Nanos is asked about reports of blood found inside Guthrie's house.

The sheriff says he's not saying if there was blood inside or outside the house. He says so far there has been no information from the lab processing the crime scene that would indicate who is responsible for Nancy Guthrie's disappearance.

Reporters ask if the police have been able to access footage from cameras at the Guthrie house.

The sheriff says they're working with camera manufacturers to get any video footage they can, but they don't have it yet.

Sheriff Nanos says Nancy Guthrie was dropped off at her home at around 9:30 pm on Saturday by relatives.

She was reported missing the next morning about 11:00 am when she didn't come to church, which raised concerns.

Nanos is asked if any demands have been made by kidnappers, and he says they have all sorts of leads they are working on.

The sheriff says authorities believe Nancy Guthrie was taken from her home against her will.

He says they've looked for DNA, fingerprints and cameras from the scene of the suspected crime.

"Those things have been submitted forward to labs," he says. "We're waiting for those returns to come back."

Image source, Reuters

The sheriff says he doesn't know if there was one or more than one perpetrator in this case.

He's asked if, at this point, police are still trying to find Nancy Guthrie alive. The reporter referenced her medication which the 84-year-old takes daily.

"We hope we are," Nanos said.

The FBI's Jon Edwards adds that his agency is looking at this case from all angles, including by examining cell tower information.

But they need the public's help he says. He asks if anyone has seen something on Saturday night, to please call the FBI.

Sheriff Nanos says police plan to do a briefing every couple of days on this case, unless there is a major development.

He introduces Jon Edwards, the FBI liaison from Tucson who says the FBI is doing everything to bring Svannah Guthrie's mother home.

"We are looking at this from every angle, but we need your help," he says.

Pima County Sheriff Chris Nanos is first to speak.

He says they have a lot of work ahead and that someone's life is in jeopardy.

"Job number one is we gotta find her," he says, referring to missing Nancy Guthrie.

The police news conference on the disappearance of Nancy Guthrie has started.

We are hearing from Pima County Sheriff Chris Nanos.

We will bring you the key lines here and you can click Watch live above to stream it.

Earlier today, the White House posted about the search for Nancy Guthrie, urging anyone with information to call 911.

The search is ongoing, the post says, and authorities "are requesting assistance from the public".

"Our prayers are with the Guthrie family as we hope for Nancy's safe return home," it adds.

On Monday evening, NBC anchor Savannah Guthrie took to social media to call for prayers as the search for her mother stretched into a third day.

"Please pray," she posted on her Instagram account. "We believe in prayer. We believe in voices raised in unison, in love, in hope. We believe in goodness...

"Thank you for lifting your prayers with ours for our beloved mom, our dearest Nancy, a woman of deep conviction, a good and faithful servant. Raise your prayers with us and believe with us that she will be lifted by them in this very moment. We need you."

Image source, NBC via Getty Images

Nancy Guthrie's disappearance is being treated as a crime, Pima County Sheriff Chris Nanos said at a news conference on Monday.

He says they came to that conclusion after rescue volunteers and others didn't find Gutherie after hours of searching near her home, and investigators assessed the conditions inside her house.

"We saw some things at the home that were concerning to us," Sheriff Nanos said. "We believe now after we processed that crime scene that we do in fact have a crime."

Nanos added that Guthrie was an 84-year-old with physical limitations, suggesting she could not have not far on her own. He also said she needed medications that if "she doesn't have in 24 hours, it could be fatal."

Image source, PIMA COUNTY SHERIFF

Officials in Pima County, Arizona are about to give an update on the search for Nancy Guthrie, mother of journalist Savannah Guthrie.

The 84-year-old has been missing since last Saturday.

Nancy Guthrie was last seen in her house outside Tucson, Arizona, on Saturday evening. Her family reported her missing a day later.

On Monday, the county sheriff said Nancy Guthrie had likely been abducted and "didn't go willingly" from her home.

A news conference is scheduled for 13:30 ET (18:30 GMT) to update the public on the incident. You can click watch live at the top of this page to follow along.