Massachusetts State Police say they have arrested three people and seized three kilograms of the powerful opioid fentanyl.
The suspects, all residents of Boston, are scheduled to be arraigned Monday on drug charges following their arrests Friday.
The investigation has been ongoing for several months and included several undercover purchases of drugs.
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Police decided to move in Friday after finding out the suspects would be possession of a large amount of the drug.
The suspects were arrested at a Dorchester shopping center with three duct-taped bricks of fentanyl in a backpack.
The suspects were identified as 48-year-old Pablo Alberto Arias Herrera; 31-year-old Omar Medina-Santiago; and 26-year-old Julio Missael Ramirez Peguero. It could not be determined if they have lawyers who could address the allegations.