Federal authorities are investigating letters with “suspicious substances” that have been mailed to congressional and election offices nationwide — including U.S. Sen. Chris Murphy’s office — and are urging recipients to treat the mailings as “potentially hazardous.”
The investigation by the FBI, U.S. Postal Inspection Service and U.S. Capitol Police was first 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.”
In Congress, the threat appeared limited to the Senate, though the House was monitoring the situation, according to a person familiar with the matter who was not authorized to discuss the investigation publicly.
The letter targeted Murphy’s office in Hartford, and it was intercepted by law enforcement, according to the senator’s spokesperson Josh Sorbe.
“Sen. Murphy’s office was sent a letter with a suspicious substance. Our office was promptly informed of the letter by FBI, SAA, and Capitol Police, and we continue to work closely with them and federal law enforcement,” Sorbe said in a statement.
“Due to those efforts and various safety protocols, the Senator and staff were not in immediate danger,” he continued. “Our office is grateful for the investigators involved in this incident, and we intend to continue close coordination as the investigation continues.”
Murphy is currently traveling around the country to help boost Democratic candidates ahead of the midterm elections. He campaigned with Angie Nixon, who’s running for the Senate in Florida, a day earlier. On Thursday, Murphy traveled next to Tennessee to campaign with Justin Pearson, who’s seeking a U.S. House seat.
An FBI statement said the bureau and the Postal Inspection Service were “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,” the statement read. “We are also working with our partners to identify the individual or individuals responsible for the letters.”
Mailed packages containing a powdery substance led to the evacuation this week of election offices in at least two states, Louisiana and Oklahoma. The Ohio secretary of state said the Postal Service intercepted a package containing a white powder intended for its office and noted that similar mailings had been sent to election officials in multiple states. Maryland, Mississippi and South Dakota officials on Thursday said their election offices also were targeted by separate mailings but that the letters were intercepted by the Postal Service.
News of the letters comes just three weeks before Election Day and is reminiscent of a similar threat in 2023, when election offices in six states received mailings that contained a white powder. In some cases, the incidents disrupted work around local elections.
Some of those letters contained threats and traces of the powerful opioid fentanyl, leading some election offices to stock up on the overdose reversal medication naloxone.
The National Association of Secretaries of State and the National Association of State Election Directors issued a joint statement condemning what they said were threats against election staff.
“Those who administer our elections should never fear for their safety while carrying out their essential duties,” they said in their statement.
Deputy Postal Inspector Brendan Donahue told reporters Thursday that “any threat or attack on election officials is unacceptable” and that “we are also working with our partners on identifying the individual or individuals responsible for the letters.”
Associated Press writers Scott Bauer in Madison, Wisconsin; Sarah Rankin in Richmond, Virginia; and Nicholas Riccardi in Denver contributed to this report.

