For the first time in the Jessica Ridgeway murder case, investigators released the description of man who used a chemical-soaked rag in an unsuccessful attempt to abduct a 22-year-old woman near Ketner Lake on May 28. 
 
 Police stressed in their announcement on Thursday that they are linking the two cases in "an attempt to uncover any lead" in the Jessica Ridgeway's Oct. 5 abduction and subsequent murder and dismemberment. 
 
 "Police are trying to determine if there is any connection between the two cases," authorities said in a bulletin to media Thursday afternoon. 
 
 Ketner Lake Open Space is only about a half-mile from Jessica's home and immediately south of Witt Elementary School, where she was headed that Friday morning, though she never made it. 
 
 On May 28 the young woman said she was grabbed by a man described as white or light-skinned and between 18 and 30 years old, with brown hair and a medium build. He was about 5 feet, 8 inches tall. 
 
 The woman had initially jogged past the man, police said, then he grabbed her from behind "trying to put a rag over her mouth. She said the rag had a chemical smell on it. She was able to get away and called 911 from her cell phone." 
 
 Law enforcement has no description of a vehicle related to that case, police aid. 
 
 Police have said they had no information connecting Jessica's case to any other previous metro area abduction cases . 
 
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 Westminster police also are looking at other attempted abductions in the Denver metro area to see whether those suspects could have been involved in Jessica's kidnapping on Oct. 5 , followed by the discovery of her body 11 miles away in an Arvada open space on Oct. 9. 
 
 "Several metro area law enforcement jurisdictions are working other cases of attempted abductions and various vehicle or suspect descriptions have been provided," Westminster police stated Thursday. 
 
 Investigators are asking the public to call if they know of someone whose behavior has been unusual, including failing to show up at family activities or abrupt changes in appearances or habits around Memorial Day or Oct. 5. 
 
 Anyone with information can call Westminster police at 303-658-4336 or by sending an e-mail to PDamberalert@cityofwestminster.us 
 
 Joey Bunch: 303-954-1174, jbunch@denverpost.com or twitter.com/joeybunch ||||| WESTMINSTER, Colo. - Westminster police announced Wednesday they have arrested a 17-year-old -- who has demonstrated skills in forensic science and criminology -- in the abduction and murder of 10-year-old Jessica Ridgeway. 
 
 "I'm pleased to announce that today I believe we have taken a significant step toward justice for Jessica. We have made an arrest in the Jessica Ridgeway case: 17-year-old Austin Sigg is in our custody," Westminster Police Chief Lee Birk announced during a noon news conference. 
 
 Westminster police said they received a call Tuesday evening that led them to Sigg's home near the Ketner Lake Open Space, which is about 1 mile from Jessica's home on the other side of Ketner Lake. 
 
 He was arrested at his home around 7:45 p.m. Tuesday and cooperated with police and waived his rights, according to the custody report. (See custody report.) 
 
 7NEWS has learned that a woman identifying herself as Sigg's aunt said the teen went to his mother on Tuesday with "disturbing information" and his mom urged him to call police and turn himself in. 
 
 Sigg's mother, Mindy Sigg, told reporters that she made the phone call to police and then her son turned himself in. 
 
 His mother was at the home when he was taken into custody. 
 
 Investigators said they will file charges against Sigg in the abduction and death of Ridgeway and the May 28 attempted abduction and attempted murder of a 22-year-old woman at Ketner Lake. 
 
 "We hear that there are statements involved," said CU law professor Aya Gruber. "That's usually very good evidence, but we have to bear in mind that this juvenile is presumed innocent until he's proven guilty." 
 
 The Supreme Court of the United States, in the June ruling in the Miller v. Alabama case, decided that mandatory life sentences without the possibility of parole are unconstitutional for juvenile offenders. Additionally, the Supreme Court ruled in Roper v. Simmons that the death penalty was cruel and unusual for people who committed crimes while under the age of 18. 
 
 "The law and medical science assumes that because he's a juvenile his brain functions different than if he were an adult. And so the law takes that into account,” said Denver attorney David Beller. 
 
 Sigg does not appear on any Colorado sex offender lists and since he is a juvenile, his previous record has been sealed. 
 
 He is being held at the Mount View Youth Services Detention Center. 
 
 Sigg expressed interest in forensic science 
 
 Sigg is currently a student at Arapahoe Community College. 
 
 He 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. 
 
 Police search homes in Westminster, Parker 
 
 Crime scene investigators descended on his home Wednesday afternoon and towed away a bronze Jeep. They erected two white tents in his driveway where they were putting items of evidence they were pulling from his home. They put up police tape all around his home and AirTracker7 video shows investigators going through the back yard. 
 
 The neighborhood around Sigg's home at 10622 W. 102nd Ave. will be closed off to everyone but residents living in that area for the next several days, Westminster police said. 
 
 Sigg has lived in this home since he was an infant. 
 
 His father -- who divorced his mother in 2000 -- still owns a home in Parker. CALL7 Investigators have confirmed that deputies, along with several FBI agents, are also searching that home on Wednesday. 
 
 Police said anyone who has any information about Sigg after seeing his photo can still call the tip line at 303-658-4336 or email: PDamberalert@cityofwestminster.us. 
 
 The investigation is ongoing and any information about Sigg that could be helpful is still welcome. 
 
 However, affidavits in the case have been sealed. 
 
 "Justice for Jessica is a process and this is the beginning of that process. I know you are yearning for a lot of information, but we can't give you a lot of information," Jefferson County District Attorney Scott Storey said during the news conference. 
 
 "Charges are forthcoming. Charges will be filed within a couple of days and then we start a different process," Storey said. "Mr. Sigg has a presumption of innocence and we are going to honor that. And that is all I have to say." 
 
 Sigg is in Jefferson County court Thursday morning for an initial appearance. He will not be formally charged until later. According to the custody report, he is facing two charges of first-degree murder, attempted murder, and second-degree kidnapping. 
 
 Jessica's Family Elated 
 
 A 7NEWS photographer who was outside Jessica's home during the Wednesday news conference said that the door to the house opened and he heard laughing inside. The mood at Jessica's home appeared to be relaxed. 
 
 "This morning the Ridgeway family was notified of this arrest. We hope and pray that this arrest gives them some measure of closure in dealing with this horrible tragedy and loss that they have suffered. We hope also that knowing that an arrest was made in this case will help our community to rest a little easier," Birk said. 
 
 Jessica's great-grandmother said she was elated to hear the news. 
 
 "Grateful to God that the community pulled together and the police department didn’t quit," said Donna Moss, who lives in Independence, Mo. "I'm feeling wonderful knowing that monster is off the streets. I'm so grateful to everybody out there who has bent over backwards." 
 
 When asked what she thinks about it being a 17-year-old suspect, Moss said, "It did surprise me. I thought he would be older than that. And, I just, my heart goes out to his mother because I can't understand how it would have to feel to be a mother of a monster like him." 
 
 "(Jessica's) dad is not having an easy time. He's not. And, he's trying his best to hold it together and go on with life, but he's pretty angry. Anger is a natural feeling for someone who has experienced what we went through," Moss said. "We'll be happy when we get the body back and can hold a funeral." 
 
 Neighbors who have been on edge for more than two weeks said they are relieved now that an arrest has been made. 
 
 "It's great. I'm so glad because ... my granddaughter ... lives right across the street and I had to pick her up and take her to school. We were afraid to walk down the street. I mean, I work right over here and we wouldn’t even walk. We’d drive to pick her up because I didn’t walk, I was just afraid. But I’m so grateful they’ve gotten somebody, I was afraid it was going to happen again," said resident Cindy Hauser. 
 
 "Every parent in every Colorado community will rest a little easier tonight. While we still mourn the death of Jessica Ridgeway, we are relieved an arrest has been made and the pursuit of justice can continue. We are especially grateful today to law enforcement officers at all levels for their quick action in this case," Gov. John Hickenlooper said in a news release. 
 
 "There's relief of course, that there’s a suspect in custody. Horror for the poor family of both this boy and Jessica. It’s been an ordeal for us too in the neighborhood, it’s just hard to express it," said neighbor Janet Bruchmann. "I think it's the massive effort that has been so impressive and these wonderful police officers leaving no stone unturned ... Your heart breaks for both the child that was killed and the child who will now face ... I can’t imagine what kind of life ... it’s just tragic in all fronts." 
 
 However, many neighbors expressed shock that the suspect could be Sigg. They described him as quiet but friendly. 
 
 "It was just like, 'Wow.' It was somebody I would not even have expected. My stomach got sore, the hand shakes. It was like, wow, this is somebody you see everyday walking down the street. We would say 'Hi.' He would say 'hi' back," said neighbor Sean Tillery. "One time he replied back, 'I like your son’s swing.' ... This was just too close to home. It just makes your stomach sick, just very nervous, it was just right around, just 5 houses away." 
 
 Sigg's former classmates at Standley Lake High said he was smart and nice and walked and talked to kids who looked like they were alone. He enjoyed computers, liked computer games, helped in the computer lab and bragged about his skills to hack into computer programs. 
 
 They say Sigg walked his younger brother to school every day. 
 
 The 2011 Standley Lake High School yearbook showed that he was involved in a school play. 
 
 Case History 
 
 Ridgeway disappeared Oct. 5 as she was walking to meet up with friends at Chelsea Park so they could all walk to school together. The park is several blocks from her home. Her friends said she never showed up at the park. 
 
 Ridgeway's remains were found in an Arvada open space park five days later. Her body had been dismembered and sources told 7NEWS that investigators were still searching for her remaining body parts. 
 
 Westminster police told 7NEWS on Tuesday that they had received 3,400 tips via email and 6,000 phone tips. 
 
 Ridgeway Case Linked To May Attack 
 
 On Monday, Westminster police confirmed to 7NEWS they found a direct connection between the murder of Jessica Ridgeway and the person who attacked a female jogger at Ketner Lake in May. 
 
 "We are able to make a definitive link," said Westminster Police spokesman Trevor Materasso. 
 
 In the May attack, a 22-year-old woman was jogging when someone grabbed her from behind and tried to put a chemical-laced rag over her mouth, police said. 
 
 The woman escaped and called 911, police said. Yet officers searching the area with a police dog were unable to find the attacker. 
 
 The suspect in the May attack was described as a light-skinned man who ranged in age from 18 to his 30s. He had brown hair, a medium build and was about 5 feet 6 inches to 5 feet 8 inches tall. The man was wearing a dark blue baseball cap, small-rim sunglasses, a black T-shirt and blue jeans. 
 
 A similar incident occurred in July 2010, when a man chased a female jogger near the lake. Police said that man's description was similar to the assailant in the jogger attack. 
 
 DNA Taken From 500 People 
 
 Westminster Police confirmed to 7NEWS that DNA samples were collected from about 500 people during the investigation. 
 
 Everyone who submitted DNA samples in the case did so voluntarily, said Materasso. Samples were collected orally, using a DNA swab. 
 
 Materasso said people were asked to provide a DNA sample if they used their cell phones near the three crime scene areas. 
 
 Others were asked for a sample if they were identified based on tips from the public or by police officers during neighborhood searches. 
 
 Although Materasso confirmed the samples were collected, he didn't discuss how the samples would be used in the investigation.
– A terrifying chemical-rag attack earlier this year may help police find the killer of a 10-year-old Colorado girl, the Denver Post reports. Still investigating the murder of Jessica Ridgeway, police have released a description of a young man with brown hair who allegedly tried to abduct a Denver-area woman on May 28 by putting a rag with a chemical smell over her mouth. The woman was able to escape and call 911 on her cell phone. Police say they have connected the cases "in an attempt to uncover any lead" in Jessica's abduction and murder about two weeks ago. They are also looking through other attempted abductions in the Denver area. In another development, police have found a small wooden cross with three lines etched into it that could be key to Jessica's murder, Huffington Post reports. Police have uploaded images of the cross on their Facebook site in the hope someone who knows about the cross will come forward.