TUCSON, AZ - The search for a missing 6-year-old girl will be called off late Tuesday night and investigative methods will be employed next, according to Tucson police.
An extensive landfill search and 260 tips from the public have done little to assist in the search for Isabel Mercedes Celis, who was reported missing Saturday from her Tucson home.
Police on Tuesday said most officers involved in the search effort will leave by Wednesday morning, but a command center set up near the family's home will stay in place.
Authorities have not given up hope that Isabel is alive.
The Pima County Attorney's Office is offering a $6,000 reward, which includes an anonymous donation of $5,000, for information regarding the missing girl.
Isabel's family was allowed to return to their Tucson home Tuesday, a day after authorities kept them away as they searched for clues to her disappearance from her bedroom. It was not immediately known whether they had returned.
On Monday, FBI dogs -- one that can find human remains and the other used for search and rescue -- went through the family's home and turned up information that required a follow-up, but police declined to say what that was.
A police spokesperson said Tuesday the FBI team helped police narrow their search.
Tucson police are trying to determine what happened to Isabel. Her parents say they awoke on Saturday to find her missing. Police said a window was open with the screen pushed aside.
Since Saturday, investigators and volunteers have fanned across Isabel's neighborhood and an area landfill searching for clues. Volunteers posted fliers with a photo of Isabel -- about 4 feet tall with brown hair and hazel eyes -- holding a school award.
Her parents, identified by friends as Becky and Sergio Celis, told investigators they last saw the first-grader at 11 p.m. Friday. Her mother, a nurse, was at work Saturday when her father went to wake her at 8 a.m. and discovered her missing, police said.
Police call the case a "suspicious disappearance/possible abduction."
"We're not ruling anything out of the investigation at this point because we really need to keep our mind open about all the information that's been brought to us," Police Chief Roberto Villasenor has said.
Officers have been interviewing sex offenders in the area -- a practice that has become standard in all abduction investigations.
The family said in their first public statement that they are fully cooperating with authorities.