Kayleah Wilson Update: 18-Year-Old Boyfriend Arrested For Rape, Not Murder

Kayleah Wilson (Personal Photo)

DENVER, Colo.  (CBS/AP) There's a disturbing new revelation in the case of 12-year-old Kayleah Wilson, whose decomposing body was found last week after she'd been missing since March. Police say they have arrested a former boyfriend of the victim, an 18-year-old man, for raping Kayleah.

PICTURES: Kayleah Wilson

Greeley, Colo. police said that Robert Laurencio Montoya's arrest for the sexual assault of Kayleah is "separate and distinct" from the murder investigation, but that it did stem from information gathered during the missing persons investigation.

"This arrest culminated an investigation that developed from information that probable cause existed to believe the suspect was involved in a sexual relationship with Kayleah Wilson," Greeley police spokesman Sgt. Joe Tymkowych said.

Tymkowych said the 18-year-old had previously been interviewed and cooperated with their missing person investigation.

Roberto Montoya (AP Photo/Weld County Sheriff's Office)

PICTURES: Kayleah Wilson

Montoya is currently being held on $100,000 bond on two felony charges of sexual assault on a child, and sexual assault on a child as a pattern of abuse.

Kayleah had been missing since March when her body was found Wednesday, May 19 in a ditch in an industrial area about a half-mile from her house, by a worker who was searching the ditch after a heavy rainstorm.

Montoya was arrested that same day, police said.

PICTURES: Kayleah Wilson

Two eyewitnesses previously told police they saw Kayleah at the Greeley Mall March 28, about a half-hour after her mother said she left to attend a friend's birthday party. The ditch where Kayleah's body was found is a mile from the mall, so determining whether Kayleah really was at the mall that day will be crucial to determining what happened to her, police said.

On Friday, police said they were examining a "mountain of evidence" and developing a list of people to re-interview about the disappearance and death of the 12-year-old.

Tymkowych said they still had no suspects in the slaying but are looking at a range of individuals who had the time and opportunity to kill Kayleah and don't have good alibis.

Meanwhile Greeley, an agricultural community of about 93,000 people 65 miles north of Denver, continues to grieve over the death of Kayleah.

May 21, 2010 - Kayleah Wilson Search Ends in Rain-Filled Ditch
May 19, 2010 - Did Police Find Kayleah Wilson's Body in Ditch? Too Early to ID Badly Decomposed BodyApril 7, 2010 - Kayleah Wilson Update: Community Joins Police and FBI in Search for Missing Girl
April 1, 2010-12-Year-Old Kayleah Wilson Missing: Disappeared on Way to Birthday Party