Investigators say a 14-year-old boy found dead last year in his suburban Chicago home died from an overdose of the powerful painkiller fentanyl.
Maywood police and the Cook County Medical Examiner's Office said an autopsy on Alejandro Zagal didn't initially rule on his cause and manner of death.
But the medical examiner's office said Tuesday that investigators have since determined the teen died of cyclopropyl fentanyl toxicity.
Fentanyl is an opioid that's up to 50 times more potent than heroin. Zagal's death was ruled an accident.
Zagal was found dead by a relative on Nov. 21 at the family's Maywood home.
Police say his death remains under investigation by Maywood detectives. No charges had been filed as of Tuesday afternoon in connection with his death.