(AP) - A search that set parents in the Denver area on edge last fall, had neighbors casting a suspicious eye on neighbors, and left a family grieving the loss of a 10-year-old ended with the teen suspect telling a 911 dispatcher: "I murdered Jessica Ridgeway. I have proof that I did it. He told the 911 dispatcher that some of Jessica's remains were in the crawl space at his mother's house, according to a recording of the Oct. 23 call played in court during his preliminary hearing Friday. Fifth-grader Jessica disappeared Oct. 5 after she left her house to meet a schoolmate two blocks away so they could walk to school together. A judge ordered Austin Sigg, 18, to stand trial and be held without bail for Jessica's slaying and a May attack on a jogger at Ketner Lake, which is across the street from Jessica's elementary school. In the attack on the jogger, investigator Michael Lynch testified that Sigg used homemade chloroform concocted with a recipe found on the Internet to attempt to subdue a woman. Lynch testified at the hearing that Sigg first confessed to his mother, telling her that he kidnapped Jessica as she walked past his car, bound her arms and her legs with zip ties, placed her in the back seat, drove around for a little bit, then took her to his house. He tried to strangle her, first with zip ties and later with his hands, Lynch testified. He later dismembered her, he said. An attempted murder charge was dropped by prosecutors and the judge found there wasn't enough evidence for an attempted sexual assault charge in that case. Hundreds of officers canvassed the area after Jessica's disappearance, investigated leads and took DNA samples as parents waited with their children at bus stops and thought twice about letting them out of sight. The FBI took the unusual step of asking residents to observe their family members and neighbors for suspicious behavior. One of those residents contacted authorities Oct. 19 to report Austin Sigg because of his fascination with death, Westminster Detective Luis Lopez testified. Lopez testified that Sigg attended a community college because of their mortuary sciences program. Mindy Sigg told Lynch her son appeared sick and confessed, four days after the visit from the FBI, opening the conversation by saying he was a "monster." Mindy Sigg then called 911 to say her son wanted to turn himself in and had confessed to killing the girl. Both Mindy Sigg and Austin Sigg wiped their faces with tissue as the tape was played. Jessica's mother and other family members looked down. Arraignment, where Sigg is to enter a plea, is set for March 12.