A teenager who lived just a mile from a 10-year-old Colorado girl who was abducted and killed earlier this month has been arrested in her death, along with a May attack on a runner, authorities said Wednesday.

Police in the Denver suburb of Westminster said they took 17-year-old Austin Reed Sigg into custody on Tuesday night after receiving a phone call, apparently from his mother, that led them to Sigg. He was officially arrested Wednesday.

Reached by phone, Sigg's mother told The Associated Press he turned himself in.

"I made the phone call, and he turned himself in. That's all I have to say," said Mindy Sigg, before she broke down in tears and hung up.

Police announced the arrest as agents searched the home of Sigg, a student at Arapahoe Community College. Authorities declined to elaborate on the arrest and have released few details about the investigation. Court documents have been sealed, but a police custody report said Sigg was cooperative when he was arrested and waived his rights.

Jessica Ridgeway disappeared Oct. 5 while walking to school. Her remains were found five days later in a field at a park, and police said her body was "not intact."

The arrest case came a day after police said Jessica's abduction was linked to the May 28 attempted kidnapping of a 22-year-old runner at another area park, the Ketner Lake Open Space.

In that case, a woman fought off a stranger who grabbed her from behind and put a rag that smelled of chemicals over her mouth, authorities said. Westminster investigator Trevor Materasso said Tuesday police haven't been able to determine if the substance on the rag was meant to subdue the woman.

Authorities didn't say why they think the two cases are connected, but they noted Sigg will be charged in both crimes. His first court appearance is set for 8 a.m. Thursday.

As technicians in white coveralls searched Sigg's home, neighbors described the 17-year-old as a quiet, goth boy who often work black clothes.

"He was shy and kept to himself," said Brooke Olds, 13, who usually saw Sigg alone on a skateboard or scooter.

Sigg attended Witt Elementary — the same school Jessica went to — but he moved on to middle school in 2007, before she enrolled, Jefferson County Public Schools spokeswoman Lynn Setzer said.

Jessica was on her way to Witt when she disappeared.

Sigg later attended Standley Lake High School while also taking classes at Warren Tech, a school that offers specialized training in health science, public safety, technology and other fields.

Sigg left the school district in July after finishing the 11th grade and later earned a GED. School officials don't know why he left.

Arapahoe Community College officials confirmed that he was enrolled there but refused to say what campus he attended or what he was studying.

Police said they notified the Ridgeway family of the arrest Wednesday morning. Jessica lived in Westminster with her mother, Sarah Ridgeway. Jessica's father, Jeremiah Bryant, lives in Missouri.

"We hope and pray that this arrest brings them some measure of closure in dealing with this enormous loss that they've suffered," Police Chief Lee Birk said.

The also arrest brought relief to the community, which has been on edge as authorities searched for Jessica's killer. More parents have been waiting with their children at bus stops, and high school students have volunteered to walk younger children to school to keep them safe.

"Every parent in every Colorado community will rest a little easier tonight," said Gov. John Hickenlooper, who has a 10-year-old son. "While we still mourn the death of Jessica Ridgeway, we are relieved an arrest has been made and the pursuit of justice can continue."

A steady stream of people have paid their respects to Jessica at a memorial to her at a park near her home. It has been decorated with flowers, balloons and stuffed animals.

Jessica was walking down a quiet street in her modest neighborhood when she was last seen alive. Her school backpack was found three days later in Superior, another Denver suburb about seven miles northwest of her home.

After Jessica's disappearance, more than 1,000 officers and 10 agencies, including the FBI, investigated the case, following up on more than 4,000 leads.

Authorities had long said Jessica's killer could be someone from the community. But early on, they didn't seem to have any particular suspect in mind. They asked residents to be on the lookout for anything suspicious from their bosses, friends and family members, watching for things like leaving home unexpectedly, missing appointments or changing their appearance.