COLORADO SPRINGS, Colo. -- A Fort Carson soldier accused of killing a woman and raping a teenager has pleaded not guilty by reason of insanity.

Robert Hull Marko is charged with first-degree murder in the death of 19-year-old Judilianna "Judi" Lawrence, whom he met over the Internet. According to El Paso County sheriff's investigators, Marko met Lawrence online, through his MySpace page. He's accused of taking her to a remote mountain area, sexually assaulting her and then slitting her throat. Her body was found in October 2008.

He also is accused of sexually assaulting a 14-year-old girl five days before Lawrence was killed.

At a hearing Monday, Fourth Judicial District Judge Larry Schwartz ordered an evaluation of Marko's sanity and set his trial for June 21, according to the Colorado Springs Gazette.

Marko was arrested after an informant told police that his yellow Jeep was spotted near the area the night Lawrence disappeared. When questioned, Marko led investigators to the body in a wooded area, along Old Stage Road, behind Colorado Springs' Broadmoor neighborhood, El Paso County sheriff’s investigators have said. Marko told investigators he had a disagreement with Lawrence, then took them to the place he said he left her.

Dozens of investigators searched for Lawrence in the North Cheyenne Canon area after Lawrence's mother discovered she had been exchanging e-mails with Marko after they met on MySpace. The online relationship had spanned several months, according to dates on the e-mails.

Marko's MySpace page showed photos of him in Iraq, holding weapons. On his profile, he said, "I'm becomeing (sic) a cold hearted killer and can kill without mercy or reason."

On a sex site, a person with Marko's e-mail address posted, "I'm looking for female slave in Colorado Springs, CO region ... i'm looking for possible offline relationship. I only want females in Colorado Springs region."

He also posted, "I'm looking for just about any kind of female that likes pain and it would be great if u lived in or close to Colorado Springs."

When police searched Marko’s home after his arrest, they found a DVD containing child pornography.

Marko served as a mortarman in Iraq with a unit that has suffered some of the heaviest casualties of any Fort Carson unit there. Some other members of his unit have been charged in homicides and attempted homicides.