'Suspicious' mail with DSA-linked return address triggers FBI, Capitol Hill investigation

Senior Capitol Hill staff were warned that "multiple letters containing suspicious substances" were mailed out across the country and to multiple congressional offices on Thursday.An email notice obtained by Fox News Digital sent to chiefs of staff, administrative managers and state directors said the U.S.Postal Inspection Service, the FBI and U.S.

Capitol Police were "investigating multiple letters containing suspicious substances that were mailed to various addresses nationwide, including multiple Congressional offices.""Law enforcement officials are working to intercept any additional letters before they are delivered, however, it is possible that some letters may reach their destinations," the notice from the U.S.Senate Sergeant at Arms read.ARMED MAN ARRESTED AT US CAPITOL BARRICADE AS POLICE PROBE WHY HE DROVE ONTO RESTRICTED GROUNDSA U.S.

Capitol Police officer at the Capitol in Washington, D.C., on Friday, Oct.10, 2025.

(Valerie Plesch/Bloomberg via Getty Images)The notice was first reported by Punchbowl News.An FBI spokesperson declined to confirm specific instances or letters, but said in a statement that, "The FBI and U.S.Postal Inspection Service are investigating a series of suspicious mailings sent to various addresses nationwide, including Secretary of State offices and their related election offices." "Some of the letters contained an unknown substance, and we are working closely with our law enforcement partners to respond to each incident," the spokesperson said.

"We are also working with our partners to identify the individual or individuals responsible for the letters.This FBI and the U.S.

Postal Inspection Service will continue to safeguard the public and secure elections for American citizens."DEPROGRAMMED: FORMER DSA INSIDER REVEALS ‘FRIGHTENING’ SOCIALIST AGENDA DROVE HIM FROM ‘EXTREME’ IDEOLOGYDemonstrators carry signs from the Metro DC Democratic Socialists of America during a pro-Palestinian protest in Washington on Oct.10, ...