Investigators confirmed through DNA analysis that bones found at a landfill on Nov. 18 in Savannah, Georgia, belong to missing toddler Quinton Smith, the FBI's Atlanta field office said Monday.
The 20-month-old boy was originally reported missing on the morning of Oct. 5 by his mother, 22-year-old Leilani Simon, who has since been arrested and charged with malice murder, concealing the death of another person, and other charges.
The little boy's remains were found on Nov. 18 following a 30-day search through the Superior Landfill, a process that authorities called "more grueling than anyone could have imagined."
During that search, investigators combed through 1.2 million pounds of trash in "grueling and hazardous" working conditions.
Leilani Simon was identified as a prime suspect early in the investigation and was arrested on Nov. 21.
Her son was last seen in the early morning hours of Oct. 5 at a home in Savannah, where he lived with his mom, mom's boyfriend, maternal grandparents, and siblings.
Leilani Simon told a police dispatcher later that morning that she awoke to find her son gone and believed someone had entered the room and taken him, according to local news outlet WCJL.
Law enforcement officers from the FBI, Chatham County Sheriff’s Office, Georgia Bureau of Investigation, Georgia Department of Natural resources, and other agencies assisted in the investigation and search for the toddler.
The Chatham County District Attorney is prosecuting Simon for murder and other charges.
Fox News' Rebecca Rosenberg contributed to this report.