TODAY | October 25, 2012
>> and more on that startling arrest in the kidnapping and murder of 10-year-old jessica ridgeway . a 17-year-old is behind bars and will be charged in connection with that case. this morning, miguel almaguer is in golden, colorado.
>> reporter: detectives say the suspect is a local boy, a teenager accused and responsible for a horrific crime that rocked this community.
>> reporter: police say the suspect is 17-year-old austin sigg , a teenager accused of kidnapping and murdering 10-year-old jessica ridgeway . she sappeared october 5th . the fifth grader last seen walking to school, her dismembered body discovered days later in a rural open space .
>> we can't give you a lot of information. affidavits in this case have been sealed. that's under a court order . so i'm precluded from giving too much detail.
>> reporter: arrested tuesday night after what police called a tip, nbc denver affiliate kusa reports sigg 's own mother called investigators. i made the phone call and he turned himself in. that's all i have to say, mindy sigg told the "associated press." kusa reports sigg was interrogated for six hours telling detectives, quote, specific details about the crime that only someone intimately involved would know. all day wednesday, investigators were spotted inside sigg 's family home just a mile and a half from jessica ridgeway 's house. inside, law enforcement sources reportedly say they found human remains . meantime, at standley lake high school , classmates say he collected knives and swords and described him as a brilliant student.
>> he was smart as all can be. he knew what he was doing, he had good grades, he was intelligent.
>> friends say sigg was active in online gaming . before his arrest, sigg was enrolled in community college where friends say he was fascinated with mortuary science . he won second place in the crime scene investigation division at a state conference. megan barker was sigg 's lab partner in forensic science and said sigg was interested in how bodies decomposed.
>> he was a really nice kid. he would help us with our projects, help the teacher with the computer. he was friendly.
>> police have linked sigg to an atem attempted kidnapping on a running trail not far from his home. they say he attacked a female jogger on memorial day , the victim saying the suspect tried to cover her face with a chemical-soaked rag. police call sigg 's arrest the start of justice for jessica . but for the little girl 's family and this community, there may never be peace.
>> it was so close to home . and he was just right over there. this is really scary.
>> reporter: austin sigg is expected in front of a judge at 8:00 a.m . local time . he'll be in juvenile court , but prosecutors tell nbc news they have every intent on trying him as an adult. matt?
>> miguel almaguer on this story for us, thank you very