AUGUSTA, Maine (AP) — A Maine woman has pleaded guilty to manslaughter after her 14-month-old son’s fatal overdose, which led to the discovery of $700,000 worth of fentanyl and other drugs.

Investigators went to Ashley Malloy’s home after she dialed 911 and her son Karson died in a hospital. They discovered white powder on a blanket and sheet in the bedroom where Karson had been sleeping. An autopsy determined the toddler died of complications from exposure to the powerful opioid fentanyl, law enforcement officials said.

Malloy, 22, of Oakland, pleaded guilty Wednesday to drug charges in addition to manslaughter. She will be sentenced later.

Her attorney said she didn’t understand the risk to her son, amounting to criminal negligence. The attorney said that others were trafficking drugs and that Malloy was merely an accomplice, not an active participant.

State police detectives who searched her apartment found nearly 6 pounds (2.7 kilograms) of fentanyl, more than 3 pounds (1.4 kilograms) of methamphetamine, more than a pound (454 grams) of crack cocaine, and more than $2,000 in cash.