The alleged kidnapper of Jayme Closs saw her on a school bus and planned her abduction.

-With AAP.

Before 13-year-old Jayme Closs was kidnapped and held hostage for three months, her 21-year-old alleged abductor spotted her board a school bus.

The criminal complaint released today (Monday, local time) ahead of Jake Patterson’s first court appearance in Barron, Wisconsin, detailed Jayme’s terrifying ordeal in which she was held captive in a cabin for 88 days.

Prosecutors described a brutal ordeal in which Patterson allegedly shot Jayme’s father James, 56, and then killed her mother Denise, 46 on October 15 last year.

The harrowing account came just days after Jayme ended her 88-day captivity by escaping the rural home where, according to authorities, Patterson kept her trapped under his bed for as much as 12 hours at a time.

The documents show Patterson confessed to his crimes and told police he first saw the young teen getting on the bus last autumn and decided he wanted to take her.

What followed was weeks of planning, in which Patterson stole license plates to replace his own, checked out the Closs home twice, purchased a black ski mask and shaved his head to avoid leaving any hairs at the crime scene, police said.

The documents allege on October 15, Patterson shot James Closs at the entrance to the house and then entered the house, kicking a door down to find Denise and Jayme hiding in the bathroom.

He tore the shower curtain down and found Denise "with her arms wrapped around Jayme in a bear hug".

He ordered Denise to duct-tape her daughter's mouth shut. He then wrapped tape around Jayme's wrists before shooting Denise.

After killing Jayme's parents, Patterson taped her ankles, locked her in his trunk and drove her to his home, passing squad cars with their sirens on that were responding to the shooting, he told police.

Asked what he would've done if stopped by police as he escaped the scene, Patterson said he still had the loaded shotgun in the car's front seat and "would most likely have shot at police".

He claimed he did not know Jayme's name until after her abduction and only learned the names of her parents after seeing stories about their murders on the news.

The Daily Mail have also obtained images of the house where Jayme was held. Photos show inside the cluttered and messy house, with a book titled "U.S Armed Forces Survival Guide" and an unfinished Monopoly game visible in the main living room.

The photos can be viewed here.

According to the documents, Jayme told authorities she was kept under his bed while friends or relatives visited. Patterson placed totes and laundry bins around the bed with weights stacked against them so she could not move them.

He made it clear that no one was to know she was there, "or bad things would happen to her".

He would also turn music on in his room to drown out any sounds she could make when he had visitors.

Patterson said that Jayme had tried to escape at least twice before. When she tried unsuccessfully he "struck a wall and screamed a lot to the point where he knew she was scared and … She better never try that again."

On January 10, the day of her escape, he returned home after a few hours out to find that Jayme had been able to move the items stacked against his bed. He briefly looked for her inside, before spotting footprints in the snow outside.

He hoped in his car and began searching.

Jayme had fled the house when he was out and was found by a woman - Jeanne Nutter - walking her dog.

Nutter described Jayme as thin with matted hair. Despite the below-freezing temperature, she was dressed in a light jumper and pants. No gloves, no coat. The shoes on her feet appeared to be several sizes too large - they belonged to Patterson.

"I’m lost, and I don’t know where I am, and I need help," the girl told Jeanne, according to CNN.

Jeanne took Jayme to the closest house where they called 911. Jayme provided details about Patterson's car to police, who swooped on him within minutes.

Patterson told police he assumed he had gotten away with killing James and Denise Closs and kidnapping Jayme when he hadn't been caught in the first two weeks - but when he saw police at his house after Jayme's escape he knew he was caught.

Following her rescue, Barron County Sheriff Chris Fitzgerald told media Jayme had been reunited with her family and was doing "as well as the circumstances allow".

"Jayme is the hero, in this case, there’s no question about it."

Detective Jeffrey Nelson said following a two-day search of Patterson's property, 89 pieces of evidence were recovered including a shotgun and three remaining shotgun shells, leather steel toed boots and the black clothing and balaclava Patterson wore on the night of the abduction.

Patterson appeared in court on Monday charged with two counts of intentional homicide as well as kidnapping and armed burglary.

A judge ordered he be held of a $5million bail. He will reappear in court in February.