The U.S. Capitol Police partially shut down the Senate Hart Building and the Senate Russell Building as officials investigated suspicious packages. Both buildings have been reopened, according to officials.
Washington was on heightened alert in the wake of the Boston Marathon bombings Monday, although there was no indication the letters or suspicious packages were related to the Boston events.
On Tuesday, officials said a letter addressed to Sen. Roger Wicker (R., Miss.) had been intercepted before it reached his offices. They said the Wicker letter tested positive for ricin at a mail processing facility in Baltimore. In a statement late Tuesday, the Federal Bureau of Investigation said preliminary field tests on the Wicker letter produced "inconsistent results."
Authorities noted that false positive tests for ricin are common.
The Wicker letter was sent to a military lab in Maryland for conclusive laboratory testing. It wasn't immediately clear where additional testing on the letter addressed to the president was being done.
The letter to the president was received Tuesday at a remote mail screening facility, the Secret Service said in a statement.
The FBI said the letter addressed to the White House contained "a granular substance that preliminarily tested positive for ricin.''
White House operations haven't been affected by the incident, the FBI said. "Field and other preliminary tests can produce inconsistent results,'' the FBI said.
White House spokesman Jay Carney said the president was briefed on the suspicious letters Tuesday night and again Wednesday morning.
Separately, some equipment at a different government mail screening facility tested positive for ricin Wednesday morning, the FBI said. Mail at that site is now being tested.
Also, Sen. Carl Levin (D., Mich.) said a staffer at his Saginaw, Mich., office reported a suspicious-looking letter to authorities.
The incidents brought to mind the anthrax-laced letters mailed after the Sept. 11, 2001, terrorist attacks on the World Trade Center and Pentagon. Five people were killed and 17 sickened by the anthrax. The letters raised fears that al Qaeda or another terror group had gained the ability to weaponize anthrax. The FBI eventually concluded that Bruce Ivins, a microbiologist working at an Army lab in Maryland who committed suicide in 2008, had sent the letters. Ivins's defenders question the conclusion.
Ricin is a poison found naturally in castor beans and is part of the waste product from the manufacture of castor oil.
The Centers for Disease Control and Prevention said it would take "a deliberate act to make ricin and use it to poison people." If inhaled, ingested or injected, ricin can infiltrate the cells of the body and prevent them from making needed proteins—killing the cells and causing harm, the CDC said. There is no antidote.
- Wall Street Journal
