AURORA, Colo. -- Members of a nonprofit group that specializes in finding hidden graves have joined the investigation into the possible slaying of a young girl in Aurora.

Volunteers from Fort Collins-based NecroSearch have begun searching the property where Aarone Thompson lived before she disappeared. They were called in two days after cadaver dogs searched inside and outside the home.

"What we do is look for disturbances associated with a grave," said Necrosearch's Jim Reed.

Aarone, who would be 6 years old, was reported missing last Monday, Nov. 14. Her father Aaron Thompson said she ran away from home after he would not let her have a cookie. But after three days of searching for her, police said they had received a tip leading them to believe the little girl may have been killed over a year ago. The family has lived in the home since 2001.

On Monday, the team dug in three separate locations in the back yard. Investigators placed a tent over one of those locations to shield their possible find from prying eyes, and most likely media helicopters and cameras.

During the dig, which started at 1 p.m., investigators moved buckets of dirt to another location and sifted it through a screen. Officials took away some items from the family's back yard and brought in a photographer but is is not known what the item was or if it is significant to the case.

"Much of what we do is to eliminate areas rather than to actually look for a target. It's important to note that we can't find bodies, persay, we're looking for disturbances associated with burying a body," Jim Reed said.

While the digging continued at the home on East Kepner Place, some Aurora police officers were in Detroit, meeting with Lynette Thompson, Aarone' biological mother.

With her permission, they swabbed her cheek and received a DNA sample, and talked to her about Aarone and Aarone's father. Police say they need the DNA sample because if and when they find the girl's body it will help them identify the remains.

Dogs were brought in Monday evening to help sniff out the area underneath the backyard patio.

Police said that a bed in the home believed used by Aarone was missing a mattress.

No arrests have been made in the case. Aaron Thompson and his live-in girlfriend Shely Lowe are both considered "persons of interest" by the police.

Attorney Leta Holden, who represents the family, has said that the family told her each member of the family has submitted DNA samples and fingerprints.

Holden said that Thompson and Lowe are meeting with advisors Monday night and are planning to hold a news conference on Tuesday. The family has not officially signed with an attorney.

Thompson family spokesman Sam Riddle criticized interim Police Chief Terry Jones for simply focusing on the possibility that Aarone was killed.

"It seems again like he's drawn a conclusion and then he's going on a forensic fishing expedition," Riddle said.

Police spokesman Rudy Herrera declined comment on Riddle's accusation.

"We need to make sure there's justice in this case for Aarone Thompson. We will leave no stone unturned to that end," Herrera said.

Other Kids To Remain In Protective Custody

Seven other children lived in the home with Aaron Thompson and Lowe, including Aarone's 11-year-old brother Aaron, Lowe's five children and Lowe's younger brother. All have been placed in protective custody.

A juvenile court held a hearing on the status of the children Monday but left them in protective custody, scheduling another hearing for Nov. 29, a family spokesman said.

Both Aarone's biological mother and her paternal grandmother are seeking custody of 11-year-old Aaron Jr.. Lynette Thompson lives in a woman's shelter in Detroit and participated in Monday's hearing through teleconference. She has another phone call on Tuesday to discuss her son's fate. She said she wants to bring Aaron Jr. back to Michigan while investigators look for her daughter's body.

The team of experts searching for Aarone's possible grave is a group that was formed in Colorado in 1987. One of the co-founders of Necrosearch is former Arapahoe County deputy Jack Swanburg. Swanburg said the research starts at a grave site in the hills near Highlands Ranch. There are dozens of pigs buried there and scientists study the changes in the graves over time.

"I see that this ground has been disturbed and could very well hold a cadaver of some sort," Swanburg said of the site near Highlands Ranch.

Necrosearch only assists law enforcement agencies when it is called in to help. It is a nonprofit group of volunteers who charge nothing for their expertise.

Resources:

To order a free Child Safety Kit click here
National Center For Missing and Exploited Children