The FBI is investigating a series of suspicious mailings that have been sent to various addresses nationwide, including congressional offices and state election facilities, after letters containing unknown substances were detected.
Senior staff in both the Senate and the House of Representatives were alerted to the ongoing investigation by their respective sergeants at arms. Warnings indicated that the FBI, the U.S. Postal Inspection Service, and the U.S. Capitol Police were actively examining the matter. Federal investigators are working to intercept any additional letters before they reach their intended destinations, though it is possible some may have already been delivered.
Sens. Chris Murphy, D-Conn., and Alex Padilla, D-Calif., were identified as intended recipients of mail containing suspicious substances. A spokesperson for Murphy confirmed his office received a letter with a suspicious substance, adding that due to safety protocols and law enforcement efforts, the senator and his staff were not in immediate danger. Padilla's office stated that a letter addressed to them containing a suspicious substance was intercepted by the U.S. Postal Service.
The exact nature of the substances and the total number of congressional offices targeted remain unclear. Notices sent to House staff mentioned reports of letters with suspicious white powder substances received by public officials across the United States. At the time of the notice, no House members had been identified as intended recipients, but offices were reminded to remain vigilant and follow safe mail handling procedures.
An FBI spokesperson confirmed the agency and the U.S. Postal Inspection Service are investigating the mailings, stating that "some of the letters contained an unknown substance." The FBI is working with law enforcement partners to respond to each incident and identify those responsible.
One of the envelopes included a return address linked to the Democratic Socialists of America (DSA) headquarters in New York City, according to a notice from the Senate Sergeant at Arms. A representative for the DSA told The New York Post that the organization has not occupied that office address since 2013 and is no longer headquartered there. It is unclear if the DSA has any involvement in the mailings.
The investigation comes 25 years after an anthrax-laced letter was opened in the office of then-Senate Majority Leader Tom Daschle. Mail handling procedures for Congress were significantly overhauled following that incident, with mail now processed and screened at off-site facilities before delivery.