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GOLDEN, Colo. — Jessica Ridgeway’s suspected murderer got on the telephone and told police he killed the 10-year-old girl. The call to 911 was played during his preliminary hearing Friday.

“I murdered Jessica Ridgeway,” Sigg says during the phone call. “I have proof that I did it and I’ll answer all the questions that you want.”

He then told police that he hid parts of her body in the crawl space of his mother’s house. The information came when his mother called 911 to turn her teenage son in to authorities.

In a calm voice she said, “My son admitted to murdering Jessica Ridgeway and attacking the jogger at Ketner Reservoir,” Mindy Sigg told Westminster police. “He has human remains in the crawl space of my house.”

That was on the night of October 23, nearly three weeks after Jessica Ridgeway disappeared.

More details in the Jessica Ridgeway murder case were revealed during the preliminary hearing. The court proceeding was made public thanks to a ruling from the Colorado Supreme Court.

Those new details fell in a timeline beginning when Ridgeway’s backpack was discovered and ending when Austin Sigg’s mother made the 911 call to police.

Ridgeway’s autopsy was also made public, with prosecutors saying it revealed she died of asphyxiation and suffocation by strangulation.

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According to prosecutors, authorities found Ridgeway’s missing backpack on Oct. 7, two days after she went missing. In it, they found Ridgeway’s underwear, water bottle, clothes and boots. Investigators ran the DNA from the underwear and water bottle and found that it matched an attack on a female jogger at Ketner Lake on May 28.

Three days later, prosecutors said two county workers picking up trash discovered a very heavy trash bag in an Arvada open space. They turned it over to their supervisor, who opened it and discovered a small torso with no arms or legs.

Shortly after police released a photo of a cross necklace on Oct. 19, prosecutors said authorities received a tip from a neighbor of Sigg’s, who said she believed the cross belonged to the then-17-year-old.

She said she was worried about Sigg because he was “obsessed with death and decaying human and animal bodies,” and had dropped out of school.

This public viewing of Sigg’s preliminary hearing was made possible by a ruling Thursday when the Colorado Supreme Court overturned a district court judge’s decision to close the court proceeding.

Despite appeals from his defense team, Sigg entered the hearing recognized as an adult. He was also facing three new charges as of Friday morning, according to the Jefferson County district attorney – all of them dealing with child pornography.

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Those three charges were added to the existing 19, which include 13 for the Ridgeway murder and six for the attack at Ketner Lake.

If convicted, Sigg could face life in prison. He will not be eligible to face the death penalty due to his age, 17, at the time of the crime. He is now 18.

His next court appearance is scheduled for March 12 for an arraignment and status hearing.