FBI investigates suspicious letters sent to congressional and election offices
Federal agencies are investigating mail containing unknown substances as election offices in three states report suspicious packages just weeks before the midterm elections.
By Hushread Stories, written with AI from 10 outlets · First published 15 Oct 2026
In brief
- Federal authorities are investigating suspicious letters mailed to congressional offices and election offices across the country.
- The FBI, Capitol Police and Postal Inspection Service are involved in investigating mail containing suspicious substances.
- Election officials in three states reported suspicious packages arriving at their offices during the past week.
- Letters carried a return address linked to the Democratic Socialists of America, but responsibility remains unestablished.
- Authorities are urging recipients to treat the mailings as potentially hazardous while investigators examine the substances.
Timeline · 4 moments
Authorities urge recipients to treat letters as hazardous
The Independent ↗Staff emails identify three agencies investigating congressional mail
New York Post ↗Senate staff notice describes multiple suspicious letters nationwide
ABCNews.com ↗Three states report suspicious packages at election offices
The Hill ↗How it started
Election officials in three states reported suspicious packages sent to their offices over the past week, according to The Hill. Its October 15 report described packages containing white powder, arriving only weeks before the midterm elections.
The concern extends beyond election offices. Associated Press reported that federal authorities were investigating letters containing suspicious substances mailed to congressional and election offices nationwide.
How it unfolded
By October 15, several federal agencies were investigating multiple letters mailed nationwide, according to a notice sent to Senate staff cited by ABCNews.com.
Emails sent to congressional staff on Thursday, October 15, identified the FBI, US Postal Inspection Service and Capitol Police as investigating agencies, New York Post reported. The letters were described as containing suspicious substances.
The same report said the mail carried a return address linked to the Democratic Socialists of America. A return address alone does not establish who sent a letter, and the supplied coverage does not establish responsibility.
Authorities also urged recipients to treat the letters as potentially hazardous, according to The Independent. That warning concerns how the mail should be handled, not a confirmed identification of its contents.
Where it stands
The investigation remains ongoing. CBS Top Stories described the contents as unknown substances, and the supplied coverage gives no confirmed findings about what they are or who mailed them.
The timing adds to the concern for election offices. Global News reported that the mailings came just three weeks before Election Day.
What to watch
The central unanswered questions are what the substances contain, who sent the letters and whether the congressional and election office mailings are connected. The supplied coverage does not give a timetable for findings. For recipients, the immediate guidance remains to treat the letters as potentially hazardous, according to The Independent.
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