WASHINGTON, D.C. – U.S. authorities arrested a suspect over mailings laced with the deadly poison ricin to President Barack Obama and a Senator, officials said Wednesday.
“Today at approximately 5:15 p.m. (2215 GMT), FBI special agents arrested Paul Kevin Curtis, the individual believed to be responsible for the mailings of the three letters sent through the U.S. Postal Service,” the Justice Department said.
The letters “contained a granular substance that preliminarily tested positive for ricin,” it added in a statement.
Earlier reports had said that the letters to Obama and Republican Senator Roger Wicker of Mississippi were signed “I am KC and I approve this message.”
Curtis was arrested at his home in Corinth, Mississippi, the Justice Department statement said.
The FBI said additional tests would be carried out over the next 24 to 48 hours to confirm the presence of ricin.
The U.S. Secret Service said the letter had been intercepted at a mail screening facility outside the White House on Tuesday, the same day authorities said a letter was sent to Wicker that also showed traces of ricin.
Secret Service spokesman Edwin Donovan said the agency, which protects the president and his family, worked closely with the U.S. Capitol Police and the FBI to trace the origins of the letter.
At the U.S. Capitol, sections of two Senate office buildings were briefly cordoned off amid reports of a suspicious package.
Capitol Police later said results of tests conducted at the Hart Senate office building were negative and the closed-off areas were reopened.
Senator Carl Levin issued a statement on Wednesday saying one of his staffers had discovered a “suspicious-looking letter” at a regional office in Michigan and handed it over to authorities for further investigation.
The discovery of the letters rattled nerves following the bomb attacks near the finish line at the Boston Marathon on Monday that killed three people and injured more than 180 others, though it was not clear if the incidents were linked.
The episodes also recalled the mysterious series of letters laced with anthrax that were sent to lawmakers and some journalists following the 9/11 attacks in 2001. Five people were killed from the anthrax and 17 others became ill.
Congressional mail has been screened off-site since the 2001 incident.
Three Senate office buildings were closed in 2004 after tests found ricin in mail that had been sent to the Senate majority leader’s office.
The biological agent was also sent to the White House and the Department of Transportation in November 2003. There were no injuries in those incidents.
Ricin, when inhaled, can cause respiratory problems. Ingested orally, the protein is lethal in even miniscule quantities.
Updated at 6:50 p.m. on Wednesday to include the suspect’s arrest.