Florida baby dies after 17-year-old mother gave her fentanyl in bottle

A 9-month-old baby died in Florida after its 17-year-old mother allegedly put fentanyl in his bottle before laying the infant down for a nap, authorities confirmed on Thursday.

Forensic scientists found 27 nanograms of fentanyl in the baby's body system in late June, Nassau County Sheriff Bill Leeper said in a press conference. 

"Just three nanograms (of fentanyl) is capable of killing an adult," Leeper explained, showing first a teapot and then a small bottle of pills with a minimal amount of the opioid.

On Monday, officers went to the baby's home, located in the Callahan area, after receiving an emergency call about an infant who was not breathing and had no pulse.

The baby was rushed to a Jacksonville hospital, where it was pronounced dead, Leeper added.

"Initially, the mother said she didn't know what happened. She had put the baby to sleep and just couldn't wake him up afterward," the sheriff said.

Finally, the teenage mother confessed that she was tired and wanted to take a nap, so she decided to fill the baby's bottle with "what she thought was cocaine."

The mother was charged with aggravated manslaughter and possession of a controlled substance after the baby’s death was determined to have been caused by the mother’s negligence.