A 22-year-old man detained in connection to a fatal shooting in Mansfield Saturday is facing firearms-related charges, according to the Bristol district attorney’s office.
William O’Brien, of Manchester-by-the-Sea, is charged with carrying an illegal firearm and carrying a loaded illegal firearm, prosecutors said Sunday.
He is expected to be arraigned Monday morning in Attleboro District Court.
O’Brien was detained Saturday in connection with the death of Samuel P. Waters of Mansfield. Police responding to 42 West Church St. found Waters, 23, suffering from a fatal gunshot wound just after 11 a.m. on Saturday.
The investigation is being conducted by Mansfield police as well as State Police assigned to the district attorney’s office, and is considered “extremely active,” prosecutors said.
No further information was released.
Camilo Fonseca can be reached at camilo.fonseca@globe.com. Follow him on Twitter @fonseca_esq.