SAN LUIS, Ariz. (CBS Local) — Three summer school students in Arizona were arrested Wednesday morning after they were allegedly found in possession of more than 3,200 pills of fentanyl, a potentially deadly synthetic opioid.

The students at San Luis High School were jailed and charged for drug possession and distribution charges, police said. Two of the students, Noemi Hernandez-Madrigal and Alessandra Cardenas-Hernandez, are both 18 and are being charged as adults. The third student, a 16-year-old male, will be charged as a minor.

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Hernandez-Madrigal had three separate plastic zip-lock bags containing more than 3,200 blue M30 pills, also known as fentanyl, weighing a total of 373 grams, CBS affiliate KPHO reported.

Three high school students in San Luis, Arizona, including Noemi Hernandez-Madrigal (pictured left) and Alessandra Cardenas-Hernandez (pictured right) were allegedly caught with 3,200 pills of fentanyl on June 5, 2019. (Credit: Yuma County Detention Center)

Fentanyl is a fully synthetic opioid, originally developed as a powerful anesthetic for surgery. It is also administered to alleviate severe pain associated with terminal illnesses like cancer.

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Illicitly produced fentanyl has been a driving factor in the growing opioid epidemic across the country. The rate of drug overdoses involving fentanyl skyrocketed by about 113% each year from 2013 through 2016.

“Even half a pill can kill someone. It’s happened before,” San Luis Police Lt. Marco Santana told KYMA. “We’ve had about 19 overdoses just this year alone. We’ve had about 16 in 2018 it’s obviously a very dangerous drug and there’s no control.”

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Santana said each pill costs $15 on the black market.