(CBS/AP) BOISE, Idaho -- The two couples who tipped authorities on the whereabouts of 16-year-old Hannah Anderson and her alleged kidnapper said they knew something was off when they ran into the pair in the Idaho back country.
Mark and Christa John of Sweet, Idaho, were out horseback riding with another rancher and his wife Wednesday when they ran into Anderson and 40-year-old James Lee DiMaggio. They would later recognize the girl on television as the subject of an Amber Alert.
"When they showed up to the lake it was like a square peg in a round hole - he didn't fit. He might have been an outdoorsman in California but he was not an outdoorsman in Idaho ... Red flags kind of went up," John said.
The girl ended up being Anderson, a California teen who had been missing for about a week after she was abducted by DiMaggio, a family friend also suspected of killing her mother and brother. After the tip, law enforcement officers found them Saturday afternoon, fatally shooting DiMaggio and rescuing Anderson unharmed.
Other tips that came in after the Amber Alert led investigators to Oregon after DiMaggio and the teen were reportedly spotted there. John's tip, however, helped investigators discover DiMaggio's car, hidden under brush at a trailhead on the border of the Frank Church River of No Return Wilderness in central Idaho.
John told reporters that one of the biggest red flags was that the two did not seem interested in talking, which he said was unusual for fellow campers they ran into on the trail. Something particularly strange, he said, was that the older man had a gray cat with him.
"I said, 'What are you doing with a cat here?'" John recalled, adding a cat was only good for attracting mountain lions and wolves to the area. John said the man "just kind of grinned, had a little smirk on his face," but didn't say anything.
The girl was also quiet and appeared scared, John and his wife both said. According to the couple, she said nothing except for "looks like we're all in trouble now" in response to something John said to her. The second rancher, Mike Young, said he thought it was strange she was wearing pajamas, or sweatpants, while out hiking. Yet another red flag was that all their camping gear looked brand new, John said.
It wasn't until the amber alert, however, that they realized the situation was much more serious than they had originally thought.
"For us to be there at the precise time was one chance in a trillion," Christa John said. "That was just one of those once in a lifetime events."
Law enforcement agents first spotted two people who looked like Anderson and DiMaggio on Saturday afternoon, as they flew over the wilderness area in a plane, according to a statement from Ada County Sheriff's spokeswoman Andrea Dearden.
The air was filled with smoke blown in from distant wildfires, and that made both flying and seeing the ground tough, Dearden said. The law enforcement commanders decided to send in an FBI Hostage Rescue Team immediately to get Hannah while they could.
The mountainous area is extremely steep, and the closest point where the helicopters could drop the team was more than a two-hour hike away. The agents crept close to the camp, waited until DiMaggio and Hannah separated, and then moved in.
The FBI moved the teen to an area where she could be picked up by a helicopter. The FBI won't release details about what happened between DiMaggio and law enforcement at the campsite until an investigation is complete, other than to say DiMaggio was shot and killed.
FBI Special Agent in Charge Mary Rook from Salt Lake City said the FBI will continue to work with law enforcement in both Idaho and California as the case transitions back to the San Diego Sheriff's Department.
Anderson appeared to be uninjured and was taken to an Idaho hospital where crisis counselors and health care providers were assisting her. Her father was expected to arrive in Idaho on Sunday to reunite with her.
"We will make sure she gets as much care as possible, physically and emotionally," said Dearden.
The FBI said it was sending a team to investigate what unfolded before, during and after the shooting.
The location wasn't far from where the horseback riders had spotted the pair.
The case began when the charred bodies of Hannah 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.