Who is Austin Sigg, the teen who kidnapped and killed Jessica Ridgeway?

WESTMINSTER, Colo. - A teenager who won awards for student crime scene investigations is expected to learn this week how long he'll spend in prison.

Austin Reed Sigg was described by friends as a shy, loner who was taking classes at Arapahoe Community College when he was arrested last year.

Last month Sigg pleaded guilty to kidnapping, killing and dismembering 10-year-old Jessica Ridgeway. He also pleaded guilty to trying to kidnap a jogger at Ketner Lake. She got away.

-- Sigg's school history

Sigg was enrolled at JeffCo Schools from fifth grade to 11th grade, attending Witt Elementary (the same school Jessica attended), Wayne Carle Middle School, Standley Lake High School and Warren Tech, a vocational school.

He did not graduate from Jeffco Schools but obtained his GED, a JeffCo Schools spokeswoman said.

At Warren Tech, he was involved in a student organization called HOSA, or Health Occupation Students of America, where he competed in state-wide competitions, placing as a finalist in forensic science and biotechnology categories.

Some friends have told media outlets that he expressed interest in becoming a mortician and he was studying mortuary science at Arapahoe Community College.

"He was very quiet, shy and to himself. I would say he was Gothic," said Brooke Olds, who knew Sigg for about nine years. "He never really talked about his family or his friends. Like, all he talked about was playing or spending time with us. He always wanted, just, to play capture the flag."

On his arrest report, Sigg listed his occupation as a student at Arapahoe Community College.

-- Fascination With CSI

Sigg had an interest in crime scene investigations -- or CSI. In high school, Sigg was part of HOSA, Health Occupation Students of America. He took second place with a team competing in a CSI event in the group's 2012 competition. He was also a finalist in forensic science at that same competition.

Sigg competed as a student from Warren Tech, described as "the premier Career and Technical Education center" for Jefferson County Public Schools on the district's website.

Warren Tech, which has campuses in Arvada and Lakewood, offers specialized programs, including Criminal Justice and Forensic Science.

-- Sigg's Internet Alter Ego -- Dohastvath

Sigg had a Myspace page where he used the profile name "Dohastvath." A video-gamer website stated that Dohastvath is "Austin."

Dohastvath had a YouTube account called "DNA." Both the YouTube and Myspace accounts used the same profile avatar -- a graphic image of a red-headed man in a long black coat and black pants.   

On his YouTube profile, Dohastvath commented on a song called "Stalking Your Mom," which is performed by Wax. He also has a video link to the execution of hanging of former Iraq dictator Saddam Hussein.

-- Ridgeway case

Jessica Ridgeway was abducted as she walked toward school on Oct. 5, triggering a massive search that ended with the discovery of her dismembered body five days later in an Arvada open space field.

Sigg came onto investigators' radar on Oct. 19, when a neighbor woman called a tip line in response to police saying they had recovered a small wooden cross that might have been worn by the killer.

The neighbor said she knew a kid named Austin Sigg who had worn a similar cross, according to Lopez.

The woman said she was concerned about the teen because he had dropped out of high school and "he was obsessed with death and the decomposition of bodies," the detective recalled.

Based on that tip, the FBI took a DNA sample from Sigg that day, Lopez said.

Four days later, Sigg's mother, Mindy Sigg, called 911.

"I need you to come to my house, my son wants to turn himself in for Jessica Ridgeway's murder," the mother told a dispatcher.

Then Sigg is heard on the tape telling the dispatcher, "I murdered Jessica Ridgeway, I have proof that I did. I'm giving myself up completely, there will be no resistance whatsoever."

The dispatcher asked the teen if he had a criminal history.

"The only other (incident) was Ketner Lake, where a woman was attacked. That was me," Sigg said.

Mindy Sigg also told the dispatcher that her son had hidden the girl's remains in the crawl space under the family's Westminster home.

Officers interviewed Austin Sigg at his home that night and arrested him.

Investigators said Sigg's DNA was linked to "touch" DNA found on Jessica's torso, underwear, water bottle, boots and gloves as well as the clothing of the jogger who was grabbed at Ketner Lake.

During a search of Sigg's home, police seized computer equipment.

Westminster Police Det. Chris Pyler, who specializes in crimes against children, testified during one of Sigg's hearing that child pornography images were recovered from a laptop and a computer tower seized at the home.