A Secret Service official said the letter sent to the White House was similar but did not elaborate. The White House mail screening facility turned it over to the FBI’s Joint Terrorism Task Force, the Secret Service official said on condition of anonymity.
Authorities have stopped several ricin-laced letters in recent weeks. A Tupelo, Mississippi, man was charged last month with sending poison-laced letters to Obama and two other public officials. Everett Dutschke was being held on charges of developing and possessing ricin and attempting to use it as a weapon, according to the Justice Department.
Authorities also intercepted a letter sent to U.S. Senator Roger Wicker of Mississippi. Preliminary tests showed it contained ricin.
Separately, federal authorities last week arrested a Washington state man, Matthew Ryan Buquet, who they suspect mailed a letter containing ricin to a U.S. district judge in Spokane. Buquet, 37, was charged with mailing threatening communications.
On Thursday, the FBI’s Seattle office said in a statement that a similar letter containing ricin was sent from Spokane to Obama and postmarked May 13. The letter Buquet is accused of sending to the judge in Washington state was postmarked the same day.
(Reporting by Mark Felsenthal in Washington, Alex Dobuzinskis in Los Angeles and Jonathan Kaminsky in Olympia; Editing by Doina Chiacu and Paul Simao)