An FBI complaint says 24-year-old Noah Stirn faces federal charges of interstate threats involving explosives and mailing interstate threats to injure. The Blackwater Correctional Facility inmate is already serving more than a decade in state prison for vehicle theft and witness intimidation.
Officials say Stirn sent threatening letters earlier this month to the U.S. District Court in Pensacola, the U.S. District Court in Miami, the Social Security Administration in Pensacola, the U.S. Attorney's Office in Pensacola and the Florida Department of State.
The Social Security office and the Pensacola federal prosecutor's office were evacuated last week. No explosives were reported.
FBI agents say Stirn admitted sending the letters, which he signed.
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