FBI and Postal inspectors probe suspicious substance letters mailed to congressional offices on Oct. 16
The FBI and U.S. Postal Inspection Service opened a joint investigation on Oct. 16, 2026 after letters containing an unknown substance were mailed to a series of congressional offices across the United States.
Among the recipients were the Bronx office of Rep. Ritchie Torres (D‑NY) and the Orlando office of Rep. Maxwell Frost (D‑FL). Both lawmakers said their staff notified federal, state and local authorities promptly, and that the offices were evacuated as a precaution.
Rep. Torres posted on X that the New York City Fire Department tested the material and determined it was non‑hazardous, and that the envelope had been turned over to the FBI. He added that his team would not be deterred by the incident.
Rep. Frost issued a similar statement, noting that U.S. Capitol Police and the Orlando Police Department responded, and that he and his staff were safe. He said the office would continue to cooperate with investigators as they assess the situation.
State government buildings in Arizona, including the state capitol in Phoenix, were also evacuated after receiving comparable packages. Officials in Arizona confirmed that a clerk opened a letter addressed to Secretary of State Adrian Fontes’s office before the material was identified.
Other targets reported in the investigation include Secretary of State offices in Ohio, Louisiana, and the office of former Senator Marco Rubio. In Ohio, the letter was intercepted by the U.S. Postal Service before delivery. Louisiana officials said tests found no harmful substance.
An email circulating among Capitol Hill staff showed an envelope with a return address linked to the Democratic Socialists of America, though the organization denied involvement and said it has not used that address since 2013.
Law‑enforcement partners warned that additional letters could still arrive, and urged recipients to notify authorities immediately. The FBI said it is working closely with local agencies to identify the individual or individuals responsible and to safeguard public officials ahead of upcoming elections.
Investigators continue to monitor mail streams and have asked the public to report any suspicious packages. Updates are expected as the inquiry progresses.
