Aug. 12, 2013 -- Kidnapped California teen Hannah Anderson was unaware that her mother and 8-year-old brother had been killed and was held under "extreme duress," until she was rescued by FBI agents, San Diego County Sheriff Bill Gore said today.
It was the first time authorities directly said Anderson, 16, unwillingly went with James DiMaggio, 40, who was a family friend.
Throughout the tense, six-day manhunt, which spanned thousands of miles, Anderson was kept in the dark about the deaths of her mother, Christina Anderson, 44, and brother, Ethan Anderson, 8.
It wasn't until after the interview process that an FBI forensics interviewer broke the tragic news to the teen, Gore said.
DiMaggio is suspected of killing Anderson's mother and brother, setting their house on fire, and abducting Anderson on Aug. 4.
A tip from a group of horseback riders led to the rescue of Anderson at a remote camp spot near Morehead Lake, about 75 miles north of Boise, Idaho, on Saturday.
Members of the FBI's hostage rescue team were dropped off via helicopter and climbed near-vertical terrain for two and a half hours before they moved in on DiMaggio's campsite, a federal law enforcement source said.
While few details of the rescue have been revealed, Anderson told authorities that DiMaggio fired at least one shot at the agents, prompting them to shoot and kill the suspect, Gore said.
Anderson was reunited with her father in Idaho and returned home to San Diego County late Sunday night.
Brett Anderson, Hannah's father, thanked authorities and asked for privacy for his family at a news conference today.
"The healing process will be slow," he said.
Anderson Had 'A Lot of Fear in Her Eyes'
Many details, including the circumstances and motive surrounding the double murder and abduction, remained unclear, even to authorities.
"We're continuing this investigation so we can answer all the possible questions," Gore said.
But he added, "We might never know some of these answers."
A group of horseback riders who spotted Anderson and DiMaggio on hiking trails in Idaho, said today that Anderson had "a lot of fear in her eyes" that led them to report the sighting to police and ultimately led to Anderson's rescue.
Two couples were horseback riding in the No Return Wilderness in Gem County, Idaho, on Wednesday when they saw Anderson and DiMaggio on the side of a trail, and tried to chat with them to exchange pleasantries.
"They were extremely quiet. Didn't want to engage in any kind of conversation, kind of had a bad look on their face," Mark John, one of the horseback riders and a former sheriff's deputy from Gem County, told "Good Morning America" today.
"I seen a lot of fear in her eyes and I didn't like what I seen in his eyes, so it put up a major red flag for me," Mike Young, another of the riders, said.
The riders said that after they passed by the pair, they stopped and regrouped, noting that there was something amiss with the hikers.
"Neither one of them wanted to talk. They were quite reserved. That's not like most people in the back country because in the back country, when you meet someone you want to share the experience, share the terrain, and you know, they just want to chat a little bit," Mark John said.
When they returned back home the next day and saw the report of the amber alert for Anderson, they notified authorities. Authorities quickly located a blue Nissan, owned by DiMaggio, covered in brush on Friday.
DiMaggio and Hannah's mother, Christina Anderson, "were in a close platonic relationship," according to the sheriff's department, and officials said DiMaggio might have had an "unusual infatuation" with Hannah Anderson.