Extended family of Isabel Celis is working with Pima County's 88-CRIME to offer a $6,000 reward for a substantial lead in the search for Isabel.
Six-year-old Isabel went missing from her family home in Tucson's east side sometime Friday night or Saturday morning.
The family is providing $5,000 and 88-CRIME is adding an additional $1,000.
Susie Dupnik, the executive director for 88-CRIME, says they have received nearly 70 tips.
"It's been going on 24 hours a day and all of those tips that we get we forward them to the Tucson Police Department and they follow up on them," Dupnik said.
Detectives performed a second search warrant at Isabel's home.
Sergeant Matt Ronstadt said, "At this point based on the alert or information we have received from the K9 team, there was the possibility that there were additional items of evidence that had previously been undiscovered."
Ronstadt said that the search of the Los Reales landfill concluded for the day around 4:30 p.m. Monday. Crews were 75 percent finished combing the landfill and will start searching again Tuesday morning around 6 a.m.
Ronstadt expected the crews to be finished with the landfill search by 2:30 p.m. Tucson Police Lt. Fabian Pacheco said police secured the landfill on Saturday to facilitate their search of garbage being brought into the landfill.
Investigators say there are a large number of unknowns in this case and they are not ruling anyone out as a suspect. But say they are in constant communication with the family.
Ronstadt said, " Right now the family is being treated as victims, their child is missing and we are doing everything we can to assist them in their recovery."
Multiple agencies are helping Tucson Police in their search for Isabel.
Tucson Police chief RobertoVillaseñor said the U.S. Marshal's Office, Customs and Border Protection and the FBI have offered "invaluable" assistance in the investigation.
In a news conference Monday afternoon Villaseñor said, "We are making sure we are covering everything. It is standard procedure."
Pacheco said the search, while focused on a 2.5- to 3-mile radius from the Celis home, is not limited to that radius. Pacheco said police are acting quickly to tips they have received.
Villaseñor said there have been more than 100 leads so far.
Villaseñor said the most significant lead came when one of the FBI search dogs "hit" on something. What may have caused the hit was not disclosed.
The FBI flew the dogs in from Virginia on Sunday night. One of the two dogs is a cadaver search dog, Villaseñor said. The other is trained in scent detection and identification.
Police are going back through the neighborhood, making sure to interview anyone they may have missed previously and in some cases re-interviewing people, Villaseñor said.
He said portions of the neighborhood could remain blocked off to public access for "another day or two."
Villaseñor said police are in a race against the clock, that concern grows with each passing hour.
Investigators have asked the family to leave the home during this part of the investigation.
Villaseñor said earlier Monday morning the child's window was open and the screen removed.
Detectives are looking at that as a possible suspicious point of entry.
Villaseñor says he's not ready to say there is a child predator in this case, but he did say it's always good to be vigilant about where our children are.
"We have made a point to contact every registered sex offender in the 3-mile radius," Villaseñor said.
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