'America's Most Wanted' Co-Host Says There's 'a Lot That Sticks Out' in 'Unique' Nancy Guthrie Case

Callahan Walsh is speaking out about the mysterious disappearance of Nancy Guthrie, saying there's “a lot that sticks out" to him.

The America’s Most Wanted co-host has been closely following the investigation into the Arizona mom, who vanished from her home one month ago. According to Walsh, that timeline alone makes the situation “very much a unique case.”

"The way this investigation has ebbed and flowed, it’s gone from hot, to cold, to hot [and] back to cold again," Walsh said. "Our hope is that Nancy is found alive [and] that she is brought home and reunited with her family."

Walsh also addressed Savannah Guthrie’s headline-making decision to offer up to $1 million for information leading to her mother’s recovery. He believes the reward could push someone to finally speak up.

"This amount of money is life-changing. This could really get somebody to second guess why they’ve not been truthful about what they know and could be the reason that they finally come forward with that piece of information that the family is desperate for, that law enforcement is desperate for," Callahan said. "Information that could absolutely lead to not only Nancy’s recovery, but the apprehension of the suspects as well."

He stressed that when it comes to cases like this, every tip matters — even the smallest detail.

"As tiny as you might think it is, it might be that little bit of the puzzle that law enforcement has been looking for this whole time," Callahan told Fox News Digital.

The case hits especially close to home for the true-crime TV host, as his brother Adam Walsh was kidnapped and murdered in 1981 at just six years old.

Today, Walsh co-hosts America’s Most Wanted with his father, John Walsh, and said his parents long believed “not knowing was the hardest part” after Adam disappeared.

"The two weeks that we looked for Adam, my parents couldn’t sleep. They would do anything to get Adam back, and we know what the Guthrie family is going through," Callahan said.

In addition to his TV role, Callahan serves as executive director of the National Center for Missing and Exploited Children (NCMEC). He shared that he’s grateful Savannah is using her platform to help others, even during her family’s painful ordeal.

The NBC Today co-host pledged $500,000 to the organization — a donation Callahan said "means everything" to the nonprofit.

"Children are our most vulnerable population, but they’re our most important population. They’re our future," Callahan said. "Thanks to the generous donation … we can stand by more families."

Savannah also spoke about how the ordeal has taken a toll on her.

"We also know that we are not alone in our loss," she said in a video. "We know there are millions of families that have suffered with this kind of uncertainty."

Callahan explained that donations like this allow the nonprofit to expand its work.

He said the funding helps them "better serve the families and the children that [their] mission is out there to do."

He added: "Not only will this money go directly to the programs that help bring these kids home, but will also go to raise awareness on other cases that aren’t getting the attention they deserve."

Nancy disappeared on February 1. Investigators are now using a “signal sniffer” to try to detect faint transmissions from her pacemaker, which reportedly disconnected from its phone app around 2:30 a.m. that morning.

Despite nearly 40,000 tips and the $1 million reward up for grabs, Nancy’s whereabouts remain unknown.