The FBI has confirmed that they’re investigating “suspicious letters” sent out nationwide with “unknown substances” in them.
Fox News congressional correspondent Bill Melugin said it included some offices on Capitol Hill.
“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,” an FBI spokesperson said.
“We are also working with our partners to identify the individual or individuals responsible for the letters. This FBI will continue to safeguard the public and secure elections for American citizens,” the spokesperson added.
BREAKING: FBI confirms to @FoxNews they’re investigating suspicious letters that were sent out nationwide with unknown substances in them, including to some offices on Capitol Hill.
FBI spox:
“The FBI and U.S. Postal Inspection Service are investigating a series of suspicious…
— Bill Melugin (@BillMelugin_) October 15, 2026
More from the Associated Press:
The investigation by the FBI, U.S. Postal Inspection Service and U.S. Capitol Police was disclosed in a message from the Senate Sergeant at Arms obtained Thursday by The Associated Press. The notice, sent to Senate offices, said that law enforcement officials were working to intercept any additional letters, but “it is possible that some letters may reach their destinations.”
The mailings come just three weeks before Election Day and are reminiscent of a similar threat in 2023, when several election offices received envelopes containing the powerful opioid fentanyl.
In Congress, the situation appeared isolated to the Senate, but the House was monitoring, according to a person familiar with the matter who was not authorized to discuss the investigation publicly.
According to the New York Post, the notice included a “photo of one of the suspicious envelopes that was postmarked ‘DSA’ and gave a return address at the same Financial District building — 75 Maiden Lane — that the Democratic Socialists of America formerly listed on their membership forms.”
“DSA has not occupied this office address since 2013,” an organization representative said, according to the outlet.
“We are also no longer headquartered at 75 Maiden Lane,” the rep added.
Capitol Police probing suspicious letters mailed with DSA-linked return address https://t.co/2oQ6tBWpaI pic.twitter.com/Xc8HfOcdeY
— New York Post (@nypost) October 15, 2026
The New York Post shared further:
Congressional offices have been targeted in the past with contaminated letters, most notably in a series of anthrax attacks in 2001 that sent the deadly bacteria causing the disease to Senate offices.
One of those letters arrived at then-Senate Majority Leader Tom Daschle’s (D-SD) office in October 2001, forcing staff to seek treatment while an entire building was later decontaminated.
ADVERTISEMENTThe mailing spree killed five people and sickened at least 17.
Letters containing ricin, a poison, have also been mailed to Senate offices in the past, but no deaths resulted.
