A man has been detained over the deaths of a US couple he killed because he wanted to kidnap their teenage daughter, investigators said, a day after the girl approached a stranger on a rural road saying she had been abducted in October and held against her will.

Jake Thomas Patterson, 21, was taken into custody shortly after 13-year-old Jayme Closs sought help from a woman walking her dog in a rural, heavily wooded Wisconson neighbourhood near the small town of Gordon, about 60 miles north of Barron.

Jake Thomas Patterson
Jake Thomas Patterson (Barron County Sheriff’s Department/AP)

Jayme disappeared from her family home in Barron when her parents were killed on October 15.

During a news conference, Barron County Sheriff Chris Fitzgerald said Jayme was taken against her will. He said investigators do not believe Patterson had any contact with the family.

Mr Fitzgerald said investigators believe Patterson killed Jayme’s parents because he wanted to abduct her, and that Patterson “planned his actions and took many steps to hide his identity”.

The sheriff said investigators believe the girl was “the only target”.

Barron County Sheriff Chris Fitzgerald
Barron County Sheriff Chris Fitzgerald (Aaron Lavinsky/Star Tribune/AP)

Mr Fitzgerald said Jayme was taken to hospital but has since been medically cleared and released. She was being interviewed by law enforcement officers, he added.

A woman said she was walking her dog along a rural road on Thursday afternoon when a dishevelled teenage girl called to her for help, grabbed her and told her she was lost. Only then did the girl reveal her name.

Jeanne Nutter said on Friday that Jayme told her she had walked away from a cabin where she had been held captive not far from Ms Nutter’s home.

“I was terrified, but I didn’t want to show her that,” said Ms Nutter, a social worker who spent years working in child protection. “She just yelled ‘please help me, I don’t know where I am. I’m lost’.”

Barron County Sheriff Chris Fitzgerald at a news conference
Barron County Sheriff Chris Fitzgerald at a news conference (Jerry Holt/Star Tribune/AP

Ms Nutter said she did not want to take Jayme to her nearby home because it was too close to where she had been found, and she did not want them to be alone. She said: “My only thought was to get her to a safe place.”

The two went elsewhere in the neighbourhood, to the home of Peter and Kristin Kasinskas. Jayme was skinny and dirty, wearing shoes too big for her feet, but appeared outwardly OK, the neighbours said.

“I honestly still think I’m dreaming right now. It was like I was seeing a ghost,” Mr Kasinskas told the Minneapolis Star Tribune. “My jaw just went to the floor.”

Mrs Kasinskas said Jayme told them she did not know why she was targeted.

She added she does not really know Patterson even though he lives three doors down from her. She said she taught him middle school science but only remembered that he was quiet.

Residents at the sheriff's news conference
Residents at the sheriff’s news conference (Aaron Lavinsky/Star Tribune/AP)

Mrs Kasinskas said she did not see Patterson during the months Jayme was missing.

Jayme went missing after police discovered someone had broken into the family’s home outside Barron and shot her parents, James and Denise Closs. Jayme was nowhere to be found. The Barron County Sheriff’s Department said the girl had probably been abducted.

Detectives pursued thousands of tips, watched dozens of surveillance videos and conducted numerous searches in the effort to find Jayme. Some tips led officials to recruit 2,000 volunteers for a massive ground search on October 23, but it yielded no clues.

During the 20 minutes Jayme was in their home, Peter and Kristin Kasinskas said they tried to make her feel more comfortable. They offered her water and food, but she declined both. Jayme was quiet, her emotions “pretty flat”, Mr Kasinskas said.

Jayme told the couple she did not know where she was or anything about Gordon. From what she told them, they believed she was there for most of her disappearance.

Sue Allard, Jayme’s aunt, told the Star Tribune she could barely express her joy after learning the news on Thursday night.

“Praise the Lord,” Ms Allard said between sobs. “It’s the news we’ve been waiting on for three months. I can’t wait to get my arms around her. I just can’t wait.”