Ed Smart knows exactly what Savannah Guthrie is going through.
Twenty-three years ago, in the summer of 2002, Smart's 14-year-old daughter Elizabeth was abducted from her bed in a case that hit headlines and struck fear into parents all across the country.
It would take nine, agonizing months for her to be returned to her family safely. There were relentless hoax calls to police and, like the Guthrie family has now been cruelly forced to learn, a stream of unverifiable ransom notes.
Nancy Guthrie was abducted from her Tucson home in the early hours of Sunday morning after returning from an evening with her family. The Pima County Sheriff's Office is yet to name a suspect, and there are growing fears for the 84-year-old's health and wellbeing.
For the Smart family, who miraculously welcomed their daughter home, the memories are excruciatingly vivid.
The desperation to do anything at all possible to bring a loved one home. The inability to sleep, thinking about what they might be going through, while resisting the inevitable question - are they still alive?
'The not knowing was the worst of all.
'You have three possibilities. The possibility that they could be alive and return home. The possibility that you may never know, which to me is the worst of all, because it just leaves your mind spinning and spinning.
'And then there is the possibility that she is deceased and of course, that's very hard and very difficult.'
Lois and Ed Smart holding a press conference on June 20, 2002, days after their daughter was kidnapped at knifepoint from their home
Savannah Guthrie (center with sister Annie and brother Camron) shared this video pleading for their mother's safe return
Pedophile and religious fanatic Brian David Mitchell broke into the Smart family home in suburban Salt Lake City, Utah, while they were sleeping and kidnapped her at knifepoint.
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For nine horrific months, Mitchell and his wife Wanda Barzee held Elizabeth captive, subjecting her to constant sexual, physical and mental abuse. Finally, she was rescued and reunited with her family.
While the Smart family's case ended in a positive outcome, the family of Nancy Guthrie is now grappling with those same gut-wrenching possibilities.
'A person missing is like an open wound that never heals. You don't know, you can't answer it, you can't help it, you can't stop your mind from wandering about what is happening. It's horrendous,' Smart told the Daily Mail.
'You never think this can happen to you and your family.'
The doorbell camera to Guthrie's $1million home, where she lived alone, was disconnected at around 1.47am and another camera picked up motion minutes later. At 2.28am, her pacemaker stopped connecting to her Apple Watch. A trail of Guthrie's blood was found outside the front door but now, days into the search, her whereabouts remain unknown.
Ransom notes were sent to TMZ and two local media outlets, demanding Bitcoin in exchange for her safe return. The notes gave two deadlines - one for 5pm local time Thursday, which has now passed, and one for this coming Monday.
Investigators have not been able to confirm their authenticity but are taking them seriously with Guthries' three children - Today show host Savannah, her sister Annie and brother Camron - releasing a video statement asking for proof of life and begging for her safe return. Camron shared a second video Thursday in which he again urged the potential abductors to make contact.
While it is unclear if the notes are from the perpetrator, investigators have already foiled at least one hoax ransom demand sent to Annie and her husband Tomasso Cioni. Derrick Callela was arrested in California and hit with two federal charges over the hoax.
That was a cruelty that Smart's family also endured as they desperately sought to bring Elizabeth home. Similarly, at least one person was jailed for doing so.
'There were possibilities where it was like, this could be real, but it also could be a hoax and someone trying to extort money out of us,' Smart said.
Dealing with people trying to take advantage of the family's situation only added to the nightmare.
'The situation you're in is an emotional rollercoaster and you have to step back and try to hold your emotions at bay while you try to address these potential issues, thinking this may not be true but this might be true,' Smart said.
'It's incredibly difficult because you can't put a price on the head of someone that you dearly love and care about. You just want them back... you would do anything to bring your missing family member back. But how do you know she's still there and that you're not talking with some fictitious person?'
He added: 'They're difficult situations. And where Elizabeth was healthy, Nancy she has a pacemaker and medication she's supposed to be taking, so there are complications.'
When asked what he thinks about people who put his family, and now Guthrie's family, through that added torment, Smart said: 'I just shake my head. I think somehow they just have it in their head that they can make some quick money. But the potential consequences are just horrendous.'
Dealing with suspicion and rampant speculation is also difficult.
Family members are of course often the first people looked at when loved ones go missing.
In the early days of Elizabeth's disappearance, Smart and his brothers Tom and Dave Smart were viewed as potential suspects. Scrutiny ramped up further when an exhausted Tom gave a controversial media interview and failed a police polygraph test.
The public perception that the family might be involved led to a lower volunteer turnout at searches for the missing teen.
'We as a family knew that we did not have anything to do with Elizabeth's abduction. And we also knew that this could drag on and drag on and drag on. So we basically wanted to comply with law enforcement, answer any questions and clear ourselves, so that their focus could be on what we felt was something significant versus wasting time on the family,' he said.
In Smart's case, the family was actually still in danger from Elizabeth's kidnapper.
Around a month after she was abducted, Mitchell returned and tried to kidnap her cousin. Thankfully, his plot failed.
Smart suspects police are currently providing protection for Guthrie's family members while the hunt for the 84-year-old's kidnapper continues.
'Certainly [the danger to them] is something that has to be considered,' he said.
While Savannah and her siblings beg for answers about their missing mom, Smart hopes his daughter's story offers hope that the 84-year-old can still return home safely - even as the days pass.
His advice to Savannah and her siblings would be to hold onto that hope - and also to make sure they are looking after themselves.
'I always had this feeling inside that Elizabeth was still out there,' he said.
'Keep up hope and keep moving forward in the most positive way you can.'
'And take care of yourself. In those first few days, Lois and I couldn't sleep at all. We were worried sick to death. But taking care of yourself is really important. The mental distress that this causes is huge, and getting sleep is terribly important.'
He added: 'Just keep doing everything you can to survive.'
Nancy Guthrie was last seen on Saturday night by family. In the early hours of Sunday morning, her pacemaker stopped connecting to her Apple Watch
Police outside the home of Nancy Guthrie as the desperate search continues for the 84-year-old
He also urged the Guthrie family to keep working with law enforcement, the media, and the public to get the message out there.
'As a family, one of the great things we felt we had was the eyes and the ears of the public. Having public engagement is huge. It's so important. Somebody saw something,' he said.
'Having law enforcement's help is also huge. They've dealt with this more than anyone else has, and they have protocols. And then, you've also got media which is huge in creating lines of communication whether it's to abductor or family member that's out there.'
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'So you've got these three things.'
He said: 'Our concern was for Elizabeth: where is she? Why did somebody take her? How is she surviving? What can we do to bring her back? Those are question marks that kept running through our head over and over and over again.'
'We also knew that we wanted her to know that we were doing everything possible to bring her home.'
In Elizabeth's case, the family kept the case in media and public's attention.
Eventually it worked. The then-15-year-old was recognized by a member of public who called police, leading to her rescue. In an interview with Daily Mail last year, Elizabeth said that knowing her family loved her kept her going during her months-long ordeal.
Smart hopes the same will happen in Guthrie's case.
'We want to see a successful resolution to see Nancy back with her family and, you know, the family able to rejoice that they're together again,' he said.
But whatever the outcome, Smart believes this traumatic experience will forever change the whole Guthrie family.
'Will Savannah ever be the same? No, whether her mother is returned to her or not, she will never be same after the situation,' Smart said.
'We do fall into a new normal after time. But you still are never same as you were.'
To him, this came out in moments like his children coming home late from school and him instantly fearing the worst.
'It was a conditioned response of: are we going through this again? It completely changes the way you think about and deal with things.'
'There are so many things that change your life, and this certainly changed mine.'
'It also made me want to advocate for educating children about how to stay safe and how to deal with situations like this. I think it's so important because when you're in a situation - whether it was Elizabeth's situation or Nancy's situation - what do you do?'