Mangum is accused of buying guns from dealers in Providence, Woonsocket, Warwick, Cranston and North Kingstown, according to Neronha.
These four Providence men are alleged to have conspired with Mangun or solicited him to buy handguns: Brady Robinson, 27; Yovaniell Sostre, 25; Anthony Jaiman, 28; and Wascar Rivas, 25.
Mangum, Robinson, and Rivas will be scheduled for arraignment in Providence County Superior Court. Jaiman was arraigned Thursday in Providence County Superior Court. A warrant has been issued for the arrest of Sostre.
The indictments resulted from a multi-agency investigation that included the Providence police, the federal Bureau of Alcohol, Tobacco, Firearms, and Explosives; and the attorney general s office, officials said.