The 15-year-old boy arrested in connection with the death of 10-year-old Kiaya Campbell was charged with two counts of first-degree murder Wednesday afternoon in Adams County court.

The suspect, who initially was not named because he is under 18, was identified in open court as Aidan Zellmer,

Authorities will determine whether the case will go to adult court at the end of the month.

The District Attorney’s Office filed charges against Zellmer for first-degree murder with intent and first-degree murder by a person in a position of trust.

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Campbell was reported missing on the night of June 7. Thornton Police tweeted about the girl's disappearance at 5:55 a.m. on June 8. An Amber Alert was issued at around 1:30 p.m. that same day.

A resident who had joined in on the search for the girl found her body at around 5:30 p.m. in the area of 128th Avenue and Jasmine Court – around two miles from where she was last seen.

When Campbell was first reported missing, police said she was last seen with a 15-year-old boy. Investigators have not confirmed that this is the same boy who has been charged in her death.

Campbell was reportedly visiting her father at his home on Forest Drive before she died. He lives at the residence with his girlfriend and her twin teenage boys.

Neighbors told 9NEWS that police were often called to the home. 9NEWS requested records about how many times police have been there, but the request was denied as the records are a part of the homicide investigation.

The Department of Human Services is conducting a "Child Fatality Review" for Campbell. Although she is not specifically named, documents say the department is looking into the death of a 10-year-old killed last week.

An investigation like this happens when human services becomes aware of what the state calls "an egregious incident of abuse," neglect, near fatality or fatality involving a child. In Campbell case, she was already known to social services before her death.

9NEWS is looking into the extent social services was involved in her life.

Monarch Montessori of Denver says Campbell just finished her fifth grade year at the school a few weeks ago. There are grief counselors available to students.