KENNER - A mother who was previously investigated by the state for keeping her kids in unsuitable living conditions was arrested Thursday after her child died from an apparent fentanyl overdose.

The Kenner Police Department said the 20-month-old was found unconscious at a home on New Year's Eve after getting a report that the child was not breathing. First responders tried to revive the toddler, but the baby was pronounced dead a short while later.

Investigators later found traces of fentanyl in samples taken from the child's nose. They found small amounts of what appeared to be fentanyl, cocaine and other narcotics in the room where the child and mother slept. Police also noted syringes and other paraphernalia inside the home.

A toxicology report provided to detectives Thursday showed the child had "enough fentanyl to kill an adult" in their system, according to Kenner police. They child's mom, 34-year-old Alexis Callero, was arrested later that same day and booked on charges including second-degree murder.

"Based on the easily accessible location where the drug residue was located, the child could have easily touched that," said Michael Cunningham, commander of investigations at Kenner Police. "We believe that's possibly what happened, but we can't make an exact determination at this time."

Police added that Callero was previously investigated by the Department of Children and Family Services and has even had children removed from her custody in the past. DCFS has been notified of the investigation surround the toddler's death. 

Callero was booked for second-degree murder, second-degree cruelty to juveniles, possession of drug paraphernalia and possession of a schedule I controlled dangerous substance (Heroin). 

It's the latest in a rash of child deaths in homes that were previously reported to the state. In November, the head of the agency left her job amid mounting pressure to resign over the failures at DCFS.