GOLDEN, Colo. — The second day of a motions hearing for Austin Sigg, the teen charged with the kidnapping and murder of Jessica Ridgeway, revealed graphic and disturbing details on Friday.

Prosecutors say Austin Sigg, who turned 18 while he’s been in jail, spent 18 months searching the Internet for specific violent child pornography.

On a computer taken from his mother’s home, prosecutors say evidence shows Sigg spent endless hours viewing websites depicting gruesome photos and videos of child rape, torture and dismemberment.

Sigg’s lawyers called the evidence “inflammatory” saying it would violate their client’s right to an impartial jury.

But District Court Chief Judge Stephen Munsinger denied their motion. The pornographic evidence will be allowed in order to show part of Sigg’s mental state.

For the first time disturbing details were discussed in court about a cross that police collected at the crime scene where part of Jessica’s body was found.

An image of that same necklace was released to the public during the process of the search for Ridgeway’s killer. At the time, police did not disclose specifics as to why it was important to their search.

Sigg is charged with 18 counts for the kidnap and murder of the little girl in October 2012 as well as a separate attack on a jogger at Ketner Lake during the Memorial Day weekend five months earlier.

The victim in that attack testified Friday that she saw Sigg before the assault as they both walked around the lake. She said he suddenly chased, grabbed and assaulted her by placing a red rag over her mouth that contained a strong chemical.

She testified she picked Sigg out of a photo lineup within ten seconds after being shown six pictures by investigators. “(Sigg was) the only person I recognized,” she said.

Sigg’s lawyers tried to have the lineup thrown out but the judge denied that motion.

The defense is challenging prosecution experts who will testify Jessica was sexually assaulted.

During a hearing Thursday, they said they also want to exclude several statements Sigg made to police without the presence of his mother, Mindy Sigg.

She testified Thursday that her son told her he strangled the little girl after she asked if she would ever see her mother again.

Munsinger did not rule Thursday on the motions to exclude the statements.

The judge did rule Friday that there will be two trials for Austin Sigg. One for the charges in the Jessica Ridgeway case and one for the Ketner Lake incident.

“If these two cases are tried together, the jury will hear about rape, torture, dismemberment and strangulation.” A defense attorney argued.

The prosecution argued that all of the incidents show an escalation in Sigg’s fantasies and should all be tried together.