A Fort Carson soldier charged with raping and murdering a Colorado Springs teenager also has been charged with sexually assaulting at least one child, according to court documents released Tuesday.

Spc. Robert Marko, 21, is suspected of killing 19-year-old Judilianna "Judi" Lawrence on Oct. 10 and dumping her body in the woods west of Colorado Springs.

Prosecutors filed a first-degree murder charge and 18 other felony charges against Marko Monday. Those charges include two counts of sexual assault on a child, allegedly for incidents dating to Oct. 5, according to court documents.

The charges allege Marko sexually assaulted at least one child, whose identity, age and gender weren't released, and "threatened imminent death, extreme pain or kidnapping against the victim," according to court documents. It is unclear whether two alleged assaults occurred on one child, or whether there is a different victim for each charge.

The victim or victims are younger than 15 years old, the charges say.

Details of those charges were not included in an arrest affidavit for the Lawrence homicide.

El Paso County Sheriff's Lt. Mark Hunt, head of the investigation unit, said Tuesday a court-imposed gag order prevented him from talking about the latest charges.

Marko confessed to investigators that he drove Lawrence about three miles up Old Stage Road Oct. 10, where he had violent sex with her, according to the affidavit. He admitted blindfolding and gagging the victim before cutting her throat and leaving her to die in the woods, according to the affidavit. He led investigators to the body Oct. 13 and was arrested that day.

Marko, an Iraq war veteran, is due back in court Dec. 1.