Suspicious mail investigation spans election and Senate offices

Federal authorities were investigating suspicious mail sent to election and congressional offices across the country on Oct. 15, with some letters containing an unidentified substance. The FBI and U.S. Postal Inspection Service said they were working to respond to incidents and identify the person or people responsible. No sender had been publicly identified.

The FBI said the mailings went to addresses nationwide, including state secretary-of-state offices and other election offices. The Senate Sergeant at Arms separately notified Senate offices about suspicious letters sent to multiple congressional offices and warned that additional letters might still reach their destinations.

The public reports described an ongoing investigation, not a completed finding about who sent the mail or whether every reported mailing was connected. The substance found in some letters also remained unidentified. Authorities had not announced a definitive link between the mail sent to election offices and the letters sent to congressional offices.

Reported numbers cover different groups

CBS News reported that at least six Democratic Senate offices had been sent letters, most of which were intercepted before delivery. It also reported that top election officials in at least eight states said suspicious packages had been sent to their offices in recent days. The eight-state figure is a reported minimum for election-office accounts, not an official count of every mailing or recipient.

Votebeat, citing three election officials briefed on the investigation, reported that they had been told more than 100 letters were sent to people and groups nationwide. That figure was not an official total, and the officials did not establish how many of those letters went to election officials rather than politicians or other recipients. The reported Senate-office and election-office figures describe particular groups and should not be added together as a complete count.

CBS reported that the deputy chief inspector of the Postal Inspection Service declined to give an exact incident count or discuss possible connections, citing the ongoing investigation. The House Sergeant at Arms, in a notice reported by Roll Call, said no House members had been identified as intended recipients at that time and that the House was monitoring the situation.

State offices reported evacuations and intercepted mail

Election offices in Louisiana and Oklahoma were evacuated after receiving packages containing powdery substances, according to reporting by Roll Call. In Wisconsin, officials said tests of a received letter found that its powder was not hazardous. That result applied to the Wisconsin letter; it did not identify the substance in other mailings.

CBS also reported that election offices in several other states said suspicious mail had been intercepted before delivery. These reports describe different outcomes: some mail reached an office, some was stopped beforehand, and some prompted evacuations. They do not establish a common result for every letter or package.

The Senate notice urged offices to remain vigilant because more letters might arrive. The reports came less than three weeks before the Nov. 3, 2026, midterm Election Day. The FBI said it was working with law-enforcement partners to respond and identify those responsible; federal investigators were also trying to intercept additional mail where possible. The public reports did not identify a suspect or provide a timetable for the investigation.