By Keith Coffman

GOLDEN, Colo. (Reuters) - A teen arrested on suspicion of kidnapping and killing a Colorado girl has confessed to the crime to investigators and will likely be charged as an adult, prosecutors said Thursday.

A judge ordered Austin Sigg, 17, held without bond during a brief hearing in a Golden, Colorado, courtroom. Sigg, appearing calm, was shackled at the legs and handcuffed.

The teenager is accused of slaying 10-year-old Jessica Ridgeway. The girl from the Denver suburb of Westminster was found dismembered in a crime that left parents in the area gripped with fear, leading them to walk or drive their children to and from school.

He is also accused of trying to abduct a woman jogger in a separate case.

In arguing to deny bail to Sigg, Jefferson County deputy district attorney Hal Sargent said at the hearing that investigators have obtained "a confession and DNA evidence."

"The evidence is overwhelming," he said.

A police custody report released on Wednesday said Sigg waived his right to counsel when investigators first spoke to him, in another indication he might have discussed the crimes.

At the court hearing, Sigg's public defender said that he did not have a criminal history prior to his arrest on Tuesday evening at his home in Westminster.

Jefferson County District Court Judge Ann Gail Meinster ordered Sigg held without bond.

Sigg's family and relatives of Jessica sat on opposite sides of the courtroom during the hearing. At one point, Sigg looked back at his mother.

After the hearing, Jefferson County District Attorney Scott Storey was asked by reporters if his office planned to prosecute Sigg as an adult. "I think that's the appropriate thing to do," he said.

Ridgeway vanished on October 5 and police later confirmed that mutilated remains discovered in a park about 10 miles from the Ridgeway home belonged to the missing girl.

Investigators had in recent days linked Jessica's killing to the attempted abduction in May of a local jogger, a 22-year-old woman. In that incident, a man placed a chemical-soaked rag over her mouth but she managed to escape.

Sigg was arrested on suspicion of kidnapping and murder in the death of Jessica, and criminal attempt to kidnap and murder in the jogger case, according to the custody report.

He is due to return to court on Tuesday, when prosecutors expect to formally file charges against him.

(Writing by Alex Dobuzinskis; Editing by Paul Thomasch and Vicki Allen)