The girl, 16-year-old Hannah Anderson, was rescued Saturday afternoon after the former sheriff passed along his suspicions, allowing investigators to focus efforts on a southwest corner of wilderness in the Frank Church-River of No Return Wilderness, a 3,600-square-mile roadless preserve in the heart of Idaho.
At a news conference Sunday in Boise, 71-year-old Mark John and his three riding mates shared the details of their meeting with Anderson and James Lee DiMaggio, who was later killed in a shootout during the rescue at a remote, alpine lake.
"They just didn't fit," said John, who retired as Gem County sheriff in 1996. "He might have been an outdoorsman in California, but he was not an outdoorsman in Idaho. ... Red flags kind of went up."
Initially, it was the lack of openness on the trail and a reluctance to engage in the polite exchange of banter like so many other recreationists John has encountered during his various horseback excursions.
John and his partners on horseback were also puzzled why Anderson and DiMaggio were hiking in the opposite direction of their stated destination, the Salmon River.
But more than anything, it was their gear — or lack of it. Neither was sporting hiking boots or rain gear. The 40-year-old DiMaggio, described as an avid hiker in his home state of California, was toting only a light pack. It even appeared Anderson was wearing pajama bottoms.
The four riders — John, John's wife Christa, 68, Mike Young, 62, and his wife, Mary Young, 61 — had a second encounter with Anderson and DiMaggio later Wednesday, this one at the lake as they were getting ready to head back down the trail.
The Youngs and Johns recalled seeing Anderson soak her feet in the lake and again avoid interaction. Still, nothing about their behavior raised suspicion that DiMaggio was wanted for murder and kidnapping.
"If she was sending us signals that she was in trouble, we didn't key in on it," Mary Young said.
It wasn't until Thursday afternoon when the Johns returned home and saw the girl's photographs on the news that they made a connection. After confirming with the Youngs, Mark John immediately called Idaho State Police, setting off the investigation in Idaho.
On Friday, police found DiMaggio's car, hidden under brush at a trailhead on the border of the wilderness area.
On Saturday, after searchers spotted the pair by air, two highly specialized FBI hostage teams moved in on ground, ultimately rescuing the girl and killing DiMaggio.
DiMaggio is also suspected of killing Anderson's mother and brother at his home in Southern California.
Anderson was immediately transported to an unidentified hospital. She was expected to be reunited with her father, Brett Anderson, earlier Sunday, but authorities did not disclose any details of their meeting.
Details about the operation that ended in Hannah's rescue were being released slowly.
FBI spokesman Jason Pack said the rescue teams were dropped by helicopter about 2 1/2 hours away from where Anderson and DiMaggio were spotted by the lake. Pack said the team had to hike with up to 100 pounds of tactical gear along a rough trail characterized by steep switchbacks and treacherous footing.
The teams then surrounded the camp and waited until Anderson and DiMaggio were no longer near each other before moving in, and ultimately killing DiMaggio. Few other details about the shootout are being released pending an automatic investigation by FBI agents of everything that occurred before, during and after the shooting.
Valley County Coroner Nathan Hess said he hadn't yet received DiMaggio's body, but would be responsible for issuing a death certificate and determining whether an autopsy should be performed. Hess said he wasn't sure when his part in the investigation would begin.
On Sunday, FBI agents returned to process the scene at the camp at Morehead Lake, about 8 miles inside the wilderness border and 40 miles east of the central Idaho town of Cascade.
But authorities made clear Sunday that the rescue may have taken longer if not for the chance encounter with John and the other riders.
The case began when the charred bodies of Anderson's mother, Christina Anderson, 44, and the teen's 8-year-old brother, Ethan Anderson, were found in DiMaggio's burning house outside San Diego, near the Mexico border.
DiMaggio was close to the family. Christina Anderson's husband, Brett Anderson, has described him as a best friend and said the children thought of him as an uncle.
Authorities have said DiMaggio had an "unusual infatuation" with Hannah, although the father said he never saw any strange behavior.
An Amber Alert was issued, and tips led investigators to Oregon after DiMaggio and the teen were reportedly spotted there.
Brett Anderson didn't return telephone messages left Sunday by The Associated Press. But he issued a statement to the media Saturday expressing relief that his daughter was safe.
Hannah Darby, one of Hannah Anderson's closest friends, was elated by the news.
"I'm probably going to make a really big basket with all of her favorite things in it," she said. "It will have candy and things that are pink."