AURORA, Colo. -- Aurora police investigators have met with the Arapahoe County district attorney's office to discuss the results of their investigation so far into the disappearance of Aarone Thompson.

The 6-year-old was reported missing by her father in mid-November and police searched for her over a three-day period before declaring their search had turned into a homicide investigation. Police also said that Thompson's father and his girlfriend were "persons of interest" in the investigation.

Police have been analyzing evidence gathered at the Thompson home and other locations, but have not said what they found. 7News reported that the investigators are encouraged by what they've found so far in their search for Thompson.

Investigators are still going on the belief that the little girl may have died up to 18 months ago and said they still have not been able to find anyone who can independently confirm that Thompson has been seen recently.

The photo of Thompson that the family provided to police was from a year-and-a-half ago, when Thompson and her family visited the Grand Canyon. They have not given police any more recent photos.

While police said they won't publicly discuss evidence in the case, Thompson family spokesman Sam Riddle has challenged them to release information about what they've found out. He told the Rocky Mountain News that "the community deserves to know" what happened to Thompson.

Police said they want to interview Aaron Thompson and Shely Lowe but the two have retained lawyers and have refused to meet with police.