A Senate Sergeant at Arms notice warned Capitol Hill staff on Thursday that letters containing suspicious substances had been mailed to addresses around the country, including multiple congressional offices. The U.S. Postal Inspection Service, FBI and U.S. Capitol Police were investigating, according to the notice, which was first reported by Punchbowl News.
The notice, sent to chiefs of staff, administrative managers and state directors, said law enforcement was trying to intercept any additional letters before delivery. It cautioned that some could nevertheless reach their destinations and advised treating suspicious mail or substances as potentially hazardous.
An FBI spokesperson confirmed an investigation into suspicious mailings sent to locations nationwide, including state secretary offices and related election offices. The spokesperson said some letters contained an unknown substance and that the bureau and Postal Inspection Service were coordinating with law enforcement partners to respond and identify those responsible. The spokesperson did not confirm particular letters or incidents.
An image included with the Senate notice showed an envelope bearing a return address for the Democratic Socialists of America’s New York City headquarters. The available information does not establish that the organization sent the letters. The DSA had not responded to Fox News Digital’s request for comment at the time of its report.
A representative for the group told the New York Post that the DSA had not occupied the address shown on the envelope since 2013 and was no longer headquartered at that location. The reported address therefore does not, on its own, verify who mailed the envelope or whether the group had any involvement.
The investigation follows a significant historical precedent involving mail sent to Congress. On Oct. 15, 2001, a staff member in the office of then-Senate Majority Leader Tom Daschle opened a letter containing anthrax. The current notice’s warning about potentially hazardous mail comes on the 25th anniversary of that incident, but the supplied information does not indicate that the substances in the current mailings are anthrax or establish a connection between the events.
