(NewsNation) — Authorities are preparing for an extensive search for Quinton Simon’s body at a Georgia Waste Management landfill after the toddler was presumed dead by police last week, authorities said Tuesday.

“As with every step we have taken in this case, the need for this search was based on where the evidence led us,” Chatham County Police Chief Jeff Hadley said. “We have spent the last several days preparing and deploying extensive resources to support the search team and investigators.”

“We are not just randomly searching this landfill,” said Will Clarke, senior supervisor and resident agent of the Savannah FBI. “We have evidence — specific evidence — that leads us to this large property.”

Clarke said they have dozens of FBI agents and personnel on the scene in support of the Chatham County Police Department. They will conduct a complex and strenuous effort to search through the debris. He also said that the effort will not be easy, and the outcome is uncertain.

Quinton, the 20-month-old who went missing from his grandmother’s Savannah, Georgia, home almost two weeks ago, was presumed dead by police in a press conference on Thursday, but authorities have not yet found his body.

“Our investigation over the last eight days has led us to the heartbreaking conclusion that 20-month-old Quinton Simon is deceased,” Hadley said last week.

Officials announced Wednesday night that they believed Quinton was dead and named his mother, Leilani Simon, as the prime suspect. The mother had originally called 911 on Wednesday, Oct. 5, to report that her son was gone. But Billie Jo Howell, Quinton’s grandmother, felt her daughter was lying.

During the investigation, Chatham County police and the FBI sent a team of search dogs into Howell’s home, where Leilani Simon also lived along with her boyfriend.

Though the mother was named the “primary suspect” in Quinton’s death, police had “not made any arrest or filed any charges,” as of Thursday afternoon.

“We will only do that (charge Leilani Simon) when we feel we have everything that we need to,” Hadley said.

Hadley added that while he does not know where Leilani Simon is at the moment, his department does not believe her to be a flight risk.

The investigation into Quinton’s disappearance was upgraded to a criminal investigation the Monday after his disappearance.

Though officials believe Quinton to be dead, Hadley said officials have yet to find the toddler’s body.

“From the moment we received a 911 call reporting Quinton missing, we have conducted an exhaustive search for him. Sadly, we still have not found Quinton. But our search and our investigation will continue, and it will continue with every available resource we have in order to give Quinton’s family closure and see that justice is served in this case,” Hadley said.

When pressed for details, Hadley said he could not disclose more information for fear of jeopardizing the integrity of the ongoing investigation.

No other people were being considered for criminal charges as of Thursday afternoon.