(CNN) As Jayme Closs starts her road to recovery following her kidnapping, investigators are trying to piece together what happened during the nearly three months she was in captivity.

Jake Patterson, 21, is accused of shooting and killing Jayme's parents before abducting the 13-year-old from her northwestern Wisconsin home on October 15. Her abduction led to a search that ended Thursday when she was found alive -- and Patterson was arrested -- about 70 miles from her home.

Barron County Sheriff Christopher Fitzgerald said he does not believe her kidnapper took her across state lines. Authorities are working to track their movements over the past three months.

Jake Thomas Patterson, 21, is accused of kidnapping and first degree homicide.

"Well, right now we're looking for 88 days of evidence," Fitzgerald said. "So, we're looking for receipts, where the suspect may have been over the last 88 days. Did he take things with her? Did she go with him to the store? Did he buy clothes for her? Did he buy food?" he said.

Investigators also don't know the conditions under which she was kept in the cabin in the remote Wisconsin community of Gordon or how she escaped. It appeared Patterson hid her from his friends and other people, the sheriff said without elaborating.

"All I know is that she was able to get out of that house and get help and the people recognized her as Jayme Closs right away," Fitzgerald said.

Detectives will keep talking to Jayme, but at her own pace, to get more details to help in their investigation.

"When she wants information, we'll give it to her; and when she wants to tell us things, we'll take it from her," he said.

Jayme was the target, police say

Patterson went to the Closs home outside Barron, Wisconsin, with the intention of taking Jayme, Fitzgerald said.

"We believe Jayme was the target, and he was getting rid of possible barriers to taking her," Fitzgerald said.

JUST WATCHED Jayme Closs found alive Replay More Videos ... MUST WATCH Jayme Closs found alive 01:22

What's unclear, however, is how and why Patterson -- from the remote community of Gordon, two counties from Barron -- allegedly chose Jayme for kidnapping.

The sheriff calls it "a very well-planned out attack." As an example, Fitzgerald said Patterson shaved his head to avoid leaving any hair as evidence during the assault.

There's no evidence Patterson knew the Closses or had previous contact with them, the sheriff said.

Nearly three years ago, Patterson worked for one day at the same meat products facility where Jayme's parents worked -- the Jennie-O Turkey Store plant in Barron. Patterson quit, saying he was moving from the area, according to the company.

Authorities have said they don't believe Patterson crossed paths with Jayme's parents there. Investigators are trying to determine whether he worked at another job in the area.

The same night authorities discovered Jayme missing three months ago, police found her parents James and Denise Closs shot dead in their home.

JUST WATCHED Woman who helped missing girl describes ordeal Replay More Videos ... MUST WATCH Woman who helped missing girl describes ordeal 04:16

Shortly before 1 a.m. that night, 911 dispatchers got a call during which they could hear yelling, but no one talked to the dispatcher. When the dispatcher called back, a voicemail greeting indicated the phone belonged to Denise Closs, 46.

Police arrived to find the door kicked in, Jayme missing and her parents dead.

For months, thousands of people joined search parties as investigators received thousands of tips. The FBI offered a cash reward for information on her whereabouts, and authorities urged hunters in the area to be on the lookout for clues.

She told rescuers about time in captivity

Jayme was found Thursday outside the rural community of Gordon, where Patterson was holding her against her will in his home, authorities said.

Jeanne Nutter, who has a cabin in the Gordon area, was walking her dog on an isolated road around 4 p.m. when she saw Jayme out in the cold around dusk. Nutter said Jayme did not have a coat or gloves.

"I'm lost and I don't know where I am, and I need help," Jayme told Nutter.

Nutter and Jayme went to the closest house, the home of Kristin and Peter Kasinskas, and they called 911.

"She said to us that, 'This person killed my parents and took me,'" Kasinskas said. "She said that this person usually hides her or hides her when others are near, or when he has to leave the household. She did not go into detail about how she got out of the house or anything like that."

Ten minutes after Jayme was found, Patterson was pulled over and arrested. He was being held in Barron County's jail on preliminary charges of intentional homicide and kidnapping, and will have an initial court appearance Monday.

When deputies arrested him, he was out looking for Jayme, Fitzgerald said.

JUST WATCHED Police: Woman found Closs while walking dog Replay More Videos ... MUST WATCH Police: Woman found Closs while walking dog 01:13

Jayme was hospitalized, and later released and reunited with her relatives and dog, Molly, in Barron.

Her aunt said Jayme slept well.

"It was great to know she was next to me all night," Jennifer Smith posted on Facebook on Saturday. "What a great feeling to have her home."