Authorities in Connecticut are investigating the death of a 4-month-old boy at an unlicensed day care as a homicide after medical inspectors working the case months later found that the baby had an extremely high level of Benadryl in his blood, Fox 61 reported.

Fairfield police have not made any arrests. Investigators are now trying to determine if the homicide was intentional or accidental.

In addition to investigating Adam Seagull’s death, police will pursue possible criminal charges against the day care, the report said.

Diphenhydramine, most commonly known as Benadryl, is an antihistamine meant to treat moderate to severe cold symptoms in adults.

Seagull’s death was initially ruled an accident from Sudden Infant Death Syndrome. Deputy Police Chief Chris Lyddy says there had been no signs of trauma and the baby had not been sick.

The FDA warns against administering the medication to infants under two-years-old without a doctor’s supervision, due to increased risk of overdosing.

“We have not been able to rule out anybody,” Deputy Police Chief Chris Lyddy told the Fairfield Citizen. He said the day care had been in operation at a woman's home for 11 years.

“His infectious smile brought immediate joy to everyone who had the privilege of experiencing it,” part of the infant's obituary read. “As he would look at you with his beautiful brown eyes, your heart became bigger and fuller with love.”

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