(NewsNation) — Partial remains that were found in a landfill on Nov. 18 were those of missing 20-month-old Georgia boy Quinton Simon, the FBI said Monday.

DNA analysis of the recovered bones linked the remains back to the toddler, who had been missing for nearly two months.

The Chatham County Police Department in Georgia announced last week that officers arrested Quinton’s mother, 22-year-old Leilani Simon,’s charges include malice murder, concealing the death of another person and false statements in the connection with the disappearance and death of her son.

Quinton’s grandmother had custody of the boy at the time of his disappearance from her house, where Quinton’s mother and her boyfriend were living.

Simon reported her son missing from their home Oct. 5. The report set off an extensive investigation that weeks later became a recovery mission.

“A monumental team effort was put forth by everyone involved in bringing closure to this horrific situation,” the Atlanta FBI said in a statement Monday.

In mid-October, Chatham County Police Chief Jeff Hadley told local NewsNation affiliate WSAV-TV that investigators had evidence Quinton was dead and his mother was the sole suspect.

She was seen at a local bar just hours after federal agents left the landfill, where they were searching for the boy, WSAV reported at the time.

Simon has other children who now are in state custody, according to WSAV.